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Walia A, Shew MA, Varghese J, Lefler SM, Bhat A, Ortmann AJ, Herzog JA, Buchman CA. Electrocochleography-Based Tonotopic Map: II. Frequency-to-Place Mismatch Impacts Speech-Perception Outcomes in Cochlear Implant Recipients. Ear Hear 2024:00003446-990000000-00298. [PMID: 38880958 DOI: 10.1097/aud.0000000000001528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
OBJECTIVES Modern cochlear implants (CIs) use varying-length electrode arrays inserted at varying insertion angles within variably sized cochleae. Thus, there exists an opportunity to enhance CI performance, particularly in postlinguistic adults, by optimizing the frequency-to-place allocation for electrical stimulation, thereby minimizing the need for central adaptation and plasticity. There has been interest in applying Greenwood or Stakhovskaya et al. function (describing the tonotopic map) to postoperative imaging of electrodes to improve frequency allocation and place coding. Acoustically-evoked electrocochleography (ECochG) allows for electrophysiologic best-frequency (BF) determination of CI electrodes and the potential for creating a personalized frequency allocation function. The objective of this study was to investigate the correlation between early speech-perception performance and frequency-to-place mismatch. DESIGN This retrospective study included 50 patients who received a slim perimodiolar electrode array. Following electrode insertion, five acoustic pure-tone stimuli ranging from 0.25 to 2 kHz were presented, and electrophysiological measurements were collected across all 22 electrode contacts. Cochlear microphonic tuning curves were subsequently generated for each stimulus frequency to ascertain the BF electrode or the location corresponding to the maximum response amplitude. Subsequently, we calculated the difference between the stimulus frequency and the patient's CI map's actual frequency allocation at each BF electrode, reflecting the frequency-to-place mismatch. BF electrocochleography-total response (BF-ECochG-TR), a measure of cochlear health, was also evaluated for each subject to control for the known impact of this measure on performance. RESULTS Our findings showed a moderate correlation (r = 0.51; 95% confidence interval: 0.23 to 0.76) between the cumulative frequency-to-place mismatch, as determined using the ECochG-derived BF map (utilizing 500, 1000, and 2000 Hz), and 3-month performance on consonant-nucleus-consonant words (N = 38). Larger positive mismatches, shifted basal from the BF map, led to enhanced speech perception. Incorporating BF-ECochG-TR, total mismatch, and their interaction in a multivariate model explained 62% of the variance in consonant-nucleus-consonant word scores at 3 months. BF-ECochG-TR as a standalone predictor tended to overestimate performance for subjects with larger negative total mismatches and underestimated the performance for those with larger positive total mismatches. Neither cochlear diameter, number of cochlear turns, nor apical insertion angle accounted for the variability in total mismatch. CONCLUSIONS Comparison of ECochG-BF derived tonotopic electrode maps to the frequency allocation tables reveals substantial mismatch, explaining 26.0% of the variability in CI performance in quiet. Closer examination of the mismatch shows that basally shifted maps at high frequencies demonstrate superior performance at 3 months compared with those with apically shifted maps (toward Greenwood and Stakhovskaya et al.). The implications of these results suggest that electrophysiological-based frequency reallocation might lead to enhanced speech-perception performance, especially when compared with conventional manufacturer maps or anatomic-based mapping strategies. Future research, exploring the prospective use of ECochG-based mapping techniques for frequency allocation is underway.
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Affiliation(s)
- Amit Walia
- Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine in St. Louis, St Louis, Missouri, USA
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Aronoff JM, Soleimanifar S, Bk P. Temporal pitch matching with bilateral cochlear implants. JASA EXPRESS LETTERS 2024; 4:044401. [PMID: 38558234 PMCID: PMC10989667 DOI: 10.1121/10.0025507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/20/2024] [Indexed: 04/04/2024]
Abstract
Interaural pitch matching is a common task used with bilateral cochlear implant (CI) users, although studies measuring this have largely focused on place-based pitch matches. Temporal-based pitch also plays an important role in CI users' perception, but interaural temporal-based pitch matching has not been well characterized for CI users. To investigate this, bilateral CI users were asked to match amplitude modulation frequencies of stimulation across ears. Comparisons were made to previous place-based pitch matching data that were collected using similar procedures. The results indicate that temporal-based pitch matching is particularly sensitive to the choice of reference ear.
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Affiliation(s)
- Justin M Aronoff
- Speech and Hearing Science Department, University of Illinois at Urbana-Champaign, 901 South 6th Street, Champaign, Illinois 61820, , ,
| | - Simin Soleimanifar
- Speech and Hearing Science Department, University of Illinois at Urbana-Champaign, 901 South 6th Street, Champaign, Illinois 61820, , ,
| | - Prajna Bk
- Speech and Hearing Science Department, University of Illinois at Urbana-Champaign, 901 South 6th Street, Champaign, Illinois 61820, , ,
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Creff G, Lambert C, Coudert P, Pean V, Laurent S, Godey B. Comparison of Tonotopic and Default Frequency Fitting for Speech Understanding in Noise in New Cochlear Implantees: A Prospective, Randomized, Double-Blind, Cross-Over Study. Ear Hear 2024; 45:35-52. [PMID: 37823850 DOI: 10.1097/aud.0000000000001423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
OBJECTIVES While cochlear implants (CIs) have provided benefits for speech recognition in quiet for subjects with severe-to-profound hearing loss, speech recognition in noise remains challenging. A body of evidence suggests that reducing frequency-to-place mismatch may positively affect speech perception. Thus, a fitting method based on a tonotopic map may improve speech perception results in quiet and noise. The aim of our study was to assess the impact of a tonotopic map on speech perception in noise and quiet in new CI users. DESIGN A prospective, randomized, double-blind, two-period cross-over study in 26 new CI users was performed over a 6-month period. New CI users older than 18 years with bilateral severe-to-profound sensorineural hearing loss or complete hearing loss for less than 5 years were selected in the University Hospital Centre of Rennes in France. An anatomical tonotopic map was created using postoperative flat-panel computed tomography and a reconstruction software based on the Greenwood function. Each participant was randomized to receive a conventional map followed by a tonotopic map or vice versa. Each setting was maintained for 6 weeks, at the end of which participants performed speech perception tasks. The primary outcome measure was speech recognition in noise. Participants were allocated to sequences by block randomization of size two with a ratio 1:1 (CONSORT Guidelines). Participants and those assessing the outcomes were blinded to the intervention. RESULTS Thirteen participants were randomized to each sequence. Two of the 26 participants recruited (one in each sequence) had to be excluded due to the COVID-19 pandemic. Twenty-four participants were analyzed. Speech recognition in noise was significantly better with the tonotopic fitting at all signal-to-noise ratio (SNR) levels tested [SNR = +9 dB, p = 0.002, mean effect (ME) = 12.1%, 95% confidence interval (95% CI) = 4.9 to 19.2, standardized effect size (SES) = 0.71; SNR = +6 dB, p < 0.001, ME = 16.3%, 95% CI = 9.8 to 22.7, SES = 1.07; SNR = +3 dB, p < 0.001 ME = 13.8%, 95% CI = 6.9 to 20.6, SES = 0.84; SNR = 0 dB, p = 0.003, ME = 10.8%, 95% CI = 4.1 to 17.6, SES = 0.68]. Neither period nor interaction effects were observed for any signal level. Speech recognition in quiet ( p = 0.66) and tonal audiometry ( p = 0.203) did not significantly differ between the two settings. 92% of the participants kept the tonotopy-based map after the study period. No correlation was found between speech-in-noise perception and age, duration of hearing deprivation, angular insertion depth, or position or width of the frequency filters allocated to the electrodes. CONCLUSION For new CI users, tonotopic fitting appears to be more efficient than the default frequency fitting because it allows for better speech recognition in noise without compromising understanding in quiet.
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Affiliation(s)
- Gwenaelle Creff
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
- MediCIS, LTSI (Image and Signal Processing Laboratory), INSERM, U1099, Rennes, France
| | - Cassandre Lambert
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
| | - Paul Coudert
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
| | | | | | - Benoit Godey
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
- MediCIS, LTSI (Image and Signal Processing Laboratory), INSERM, U1099, Rennes, France
- Hearing Aid Academy, Javene, France
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Dillon MT, Buss E, Johnson AD, Canfarotta MW, O’Connell BP. Comparison of Two Place-Based Mapping Procedures on Masked Sentence Recognition as a Function of Electrode Array Angular Insertion Depth and Presence of Acoustic Low-Frequency Information: A Simulation Study. Audiol Neurootol 2023; 28:478-487. [PMID: 37482054 PMCID: PMC10948008 DOI: 10.1159/000531262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/23/2023] [Indexed: 07/25/2023] Open
Abstract
INTRODUCTION Cochlear implant (CI) and electric-acoustic stimulation (EAS) users may experience better performance with maps that align the electric filter frequencies to the cochlear place frequencies, known as place-based maps, than with maps that present spectrally shifted information. Individual place-based mapping procedures differ in the frequency content that is aligned to cochlear tonotopicity versus discarded or spectrally shifted. The performance benefit with different place-based maps may vary due to individual differences in angular insertion depth (AID) of the electrode array and whether functional acoustic low-frequency information is available in the implanted ear. The present study compared masked speech recognition with two types of place-based maps as a function of AID and presence of acoustic low-frequency information. METHODS Sixty adults with normal hearing listened acutely to CI or EAS simulations of two types of place-based maps for one of three cases of electrode arrays at shallow AIDs. The strict place-based (Strict-PB) map aligned the low- and mid-frequency information to cochlear tonotopicity and discarded information below the frequency associated with the most apical electrode contact. The alternative place-based map (LFshift-PB) aligned the mid-frequency information to cochlear tonotopicity and provided more of the speech spectrum by compressing low-frequency information on the apical electrode contacts (i.e., <1 kHz). Three actual cases of a 12-channel, 24-mm electrode array were simulated by assigning the carrier frequency for an individual channel as the cochlear place frequency of the associated electrode contact. The AID and cochlear place frequency for the most apical electrode contact were 460° and 498 Hz for case 1, 389° and 728 Hz for case 2, and 335° and 987 Hz for case 3, respectively. RESULTS Generally, better performance was observed with the Strict-PB maps for cases 1 and 2, where mismatches were 2-4 octaves for the most apical channel with the LFshift-PB map. Similar performance was observed between maps for case 3. For the CI simulations, performance with the Strict-PB map declined with decreases in AID, while performance with the LFshift-PB map remained stable across cases. For the EAS simulations, performance with the Strict-PB map remained stable across cases, while performance with the LFshift-PB map improved with decreases in AID. CONCLUSIONS Listeners demonstrated differences with the Strict-PB versus LFshift-PB maps as a function of AID and whether acoustic low-frequency information was available (CI vs. EAS). These data support the use of the Strict-PB mapping procedure for AIDs ≥335°, though further study including time for acclimatization in CI and EAS users is warranted.
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Affiliation(s)
- Margaret T. Dillon
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Division of Speech and Hearing Sciences, Department of Allied Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Emily Buss
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alec D. Johnson
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael W. Canfarotta
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Brendan P. O’Connell
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Charlotte Eye Ear Nose & Throat Associates, P.A., Charlotte, NC, USA
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An overview of factors affecting bimodal and electric-acoustic stimulation (EAS) speech understanding outcomes. Hear Res 2023; 431:108736. [PMID: 36931019 DOI: 10.1016/j.heares.2023.108736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/13/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023]
Abstract
Improvements in device technology, surgical technique, and patient outcomes have resulted in a broadening of cochlear implantation criteria to consider those with increasing levels of useful low-to-mid frequency residual acoustic hearing. Residual acoustic hearing allows for the addition of a hearing aid (HA) to complement the cochlear implant (CI) and has demonstrated enhanced listening outcomes. However, wide inter-subject outcome variability exists and thus identification of contributing factors would be of clinical interest and may aid with pre-operative patient counselling. The optimal fitting procedure and frequency assignments for the two hearing devices used in combination to enhance listening outcomes also remains unclear. The understanding of how acoustic and electric speech information is fundamentally combined and utilised by the listener may allow for the optimisation of device fittings and frequency allocations to provide best bimodal and electric-acoustic stimulation (EAS) patient outcomes. This article will provide an overview of contributing factors to bimodal and EAS listening outcomes, explore areas of contention, and discuss common study limitations.
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Dillon MT, Canfarotta MW, Buss E, Rooth MA, Richter ME, Overton AB, Roth NE, Dillon SM, Raymond JH, Young A, Pearson AC, Davis AG, Dedmon MM, Brown KD, O'Connell BP. Influence of Electric Frequency-to-Place Mismatches on the Early Speech Recognition Outcomes for Electric-Acoustic Stimulation Users. Am J Audiol 2023; 32:251-260. [PMID: 36800505 PMCID: PMC10166189 DOI: 10.1044/2022_aja-21-00254] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 05/21/2022] [Accepted: 11/28/2022] [Indexed: 02/19/2023] Open
Abstract
PURPOSE Cochlear implant (CI) recipients with hearing preservation experience significant improvements in speech recognition with electric-acoustic stimulation (EAS) as compared to with a CI alone, although outcomes across EAS users vary. The individual differences in performance may be due in part to default mapping procedures, which result in electric frequency-to-place mismatches for the majority of EAS users. This study assessed the influence of electric mismatches on the early speech recognition for EAS users. METHOD Twenty-one participants were randomized at EAS activation to listen exclusively with a default or place-based map. For both groups, the unaided thresholds determined the acoustic cutoff frequency (i.e., > 65 dB HL). For default maps, the electric filter frequencies were assigned to avoid spectral gaps in frequency information but created varying magnitudes of mismatches. For place-based maps, the electric filter frequencies were assigned to avoid frequency-to-place mismatches. Recognition of consonant-nucleus-consonant words and vowels was assessed at activation and 1, 3, and 6 months postactivation. RESULTS For participants with default maps, electric mismatch at 1500 Hz ranged from 2 to -12.0 semitones (Mdn = -5 semitones). Poorer performance was observed for those with larger magnitudes of electric mismatch. This effect was observed through 6 months of EAS listening experience. CONCLUSIONS The present sample of EAS users experienced better initial performance when electric mismatches were small or eliminated. These data suggest the utility of methods that reduce electric mismatches, such as place-based mapping procedures. Investigation is ongoing to determine whether these differences persist with long-term EAS use. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.22096523.
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Affiliation(s)
- Margaret T. Dillon
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
- Division of Speech and Hearing Sciences, Department of Allied Health Sciences, The University of North Carolina at Chapel Hill
| | - Michael W. Canfarotta
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
| | - Emily Buss
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
| | - Meredith A. Rooth
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
| | - Margaret E. Richter
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
- Division of Speech and Hearing Sciences, Department of Allied Health Sciences, The University of North Carolina at Chapel Hill
| | | | | | | | | | - Allison Young
- Department of Audiology, UNC Health, Chapel Hill, NC
| | | | - Amanda G. Davis
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
- Division of Speech and Hearing Sciences, Department of Allied Health Sciences, The University of North Carolina at Chapel Hill
| | - Matthew M. Dedmon
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
| | - Kevin D. Brown
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
| | - Brendan P. O'Connell
- Department of Otolaryngology/Head & Neck Surgery, School of Medicine, The University of North Carolina at Chapel Hill
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Zhang F, Han JH, Samy R, Xiang J. Editorial: Changes in the auditory brain following deafness, cochlear implantation, and auditory training, volume II. Front Hum Neurosci 2023; 17:1124304. [PMID: 36814434 PMCID: PMC9939885 DOI: 10.3389/fnhum.2023.1124304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 01/18/2023] [Indexed: 02/08/2023] Open
Affiliation(s)
- Fawen Zhang
- University of Cincinnati, Cincinnati, OH, United States,*Correspondence: Fawen Zhang ✉
| | - Ji-Hye Han
- Hallym University, Chuncheon-si, Republic of Korea
| | - Ravi Samy
- University of Cincinnati, Cincinnati, OH, United States
| | - Jing Xiang
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
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Arias-Vergara T, Batliner A, Rader T, Polterauer D, Högerle C, Müller J, Orozco-Arroyave JR, Nöth E, Schuster M. Adult Cochlear Implant Users Versus Typical Hearing Persons: An Automatic Analysis of Acoustic-Prosodic Parameters. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2022; 65:4623-4636. [PMID: 36417788 DOI: 10.1044/2022_jslhr-21-00116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
PURPOSE The aim of this study was to investigate the speech prosody of postlingually deaf cochlear implant (CI) users compared with control speakers without hearing or speech impairment. METHOD Speech recordings of 74 CI users (37 males and 37 females) and 72 age-balanced control speakers (36 males and 36 females) are considered. All participants are German native speakers and read Der Nordwind und die Sonne (The North Wind and the Sun), a standard text in pathological speech analysis and phonetic transcriptions. Automatic acoustic analysis is performed considering pitch, loudness, and duration features, including speech rate and rhythm. RESULTS In general, duration and rhythm features differ between CI users and control speakers. CI users read slower and have a lower voiced segment ratio compared with control speakers. A lower voiced ratio goes along with a prolongation of the voiced segments' duration in male and with a prolongation of pauses in female CI users. Rhythm features in CI users have higher variability in the duration of vowels and consonants than in control speakers. The use of bilateral CIs showed no advantages concerning speech prosody features in comparison to unilateral use of CI. CONCLUSIONS Even after cochlear implantation and rehabilitation, the speech of postlingually deaf adults deviates from the speech of control speakers, which might be due to changed auditory feedback. We suggest considering changes in temporal aspects of speech in future rehabilitation strategies. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.21579171.
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Affiliation(s)
- Tomás Arias-Vergara
- Department of Otorhinolaryngology and Head and Neck Surgery, Ludwig Maximilians University of Munich, Germany
- Faculty of Engineering, Universidad de Antioquia, Medellín, Colombia
- Pattern Recognition Lab, Friedrich-Alexander University, Erlangen-Nuremberg, Germany
| | - Anton Batliner
- Pattern Recognition Lab, Friedrich-Alexander University, Erlangen-Nuremberg, Germany
- Chair of Embedded Intelligence for Health Care and Wellbeing, University of Augsburg, Germany
| | - Tobias Rader
- Department of Otorhinolaryngology and Head and Neck Surgery, Ludwig Maximilians University of Munich, Germany
| | - Daniel Polterauer
- Department of Otorhinolaryngology and Head and Neck Surgery, Ludwig Maximilians University of Munich, Germany
| | - Catalina Högerle
- Department of Otorhinolaryngology and Head and Neck Surgery, Ludwig Maximilians University of Munich, Germany
| | - Joachim Müller
- Department of Otorhinolaryngology and Head and Neck Surgery, Ludwig Maximilians University of Munich, Germany
| | - Juan-Rafael Orozco-Arroyave
- Faculty of Engineering, Universidad de Antioquia, Medellín, Colombia
- Pattern Recognition Lab, Friedrich-Alexander University, Erlangen-Nuremberg, Germany
| | - Elmar Nöth
- Pattern Recognition Lab, Friedrich-Alexander University, Erlangen-Nuremberg, Germany
| | - Maria Schuster
- Department of Otorhinolaryngology and Head and Neck Surgery, Ludwig Maximilians University of Munich, Germany
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Landsberger DM, Stupak N, Dahl C, Aronoff JM. Musical Interval Perception With a Cochlear Implant Alone and With a Contralateral Normal Hearing Ear. Trends Hear 2022; 26:23312165221142689. [PMID: 36464788 PMCID: PMC9726843 DOI: 10.1177/23312165221142689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Music through a cochlear implant (CI) is described as out-of-tune, suggesting that musical intervals are not accurately provided by a CI. One potential reason is that pitch may be insufficiently conveyed to provide reliable intervals. Another potential reason is that the size of intervals is distorted through a CI as they would be when produced by a mistuned piano. To measure intervals through a CI, listeners selected prerecorded vowels with different fundamental frequencies to represent each note in Happy Birthday. Each listener had contralateral normal hearing (NH); repeating the experiment with their NH ear allowed for a within-subject control. Additionally, the effect of listening simultaneously to both a CI and NH ear was measured. The resulting versions of Happy Birthday were analyzed in terms of their contours, interval sizes, magnitudes, consistency, and direction. Intervals with NH ears ranged from perfect to uncorrelated with target intervals. Chosen interval size with the CI was poorer than with the NH ear for all subjects. Across listeners, chosen intervals with the CI ranged from highly correlated to uncorrelated with target intervals. That CI intervals were highly correlated with target intervals for some listeners suggests that accurate intervals can be provided through a CI. For some listeners, chosen intervals were larger than target intervals, suggesting that intervals may be perceived as too small. Overall, intervals with the combination of the NH and CI ears were similar to those with the NH ear alone, suggesting that the addition of a CI has little-to-no effect on interval perception.
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Affiliation(s)
- David M. Landsberger
- Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA,David M. Landsberger, Department of Otolaryngology, New York University Grossman School of Medicine, 550 1st Avenue, STE NBV 5E5, New York, NY 10016, USA.
| | - Natalia Stupak
- Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Cori Dahl
- Speech and Hearing Science Department, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
| | - Justin M. Aronoff
- Speech and Hearing Science Department, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA
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Gantz BJ, Hansen M, Dunn CC. Clinical perspective on hearing preservation in cochlear implantation, the University of Iowa experience. Hear Res 2022; 426:108487. [PMID: 35410721 PMCID: PMC9482999 DOI: 10.1016/j.heares.2022.108487] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/17/2022] [Accepted: 03/15/2022] [Indexed: 12/16/2022]
Abstract
Preservation of residual acoustic hearing has emerged as an important concept for those individuals undergoing cochlear implantation with residual low frequency hearing. Acoustic plus electric speech processing improves hearing outcomes in quiet, enables melody recognition, preserves spatial hearing if there is acoustic hearing in both ears and significantly improves hearing in noise. The development of our experience with acoustic plus electric processing is reviewed along with clinical trials and patient outcomes that our team has documented over the past twenty years.
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Affiliation(s)
- Bruce J Gantz
- The University of Iowa Cochlear Implant Clinical Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Iowa Carver College of Medicine, Iowa City, IA United States.
| | - Marlan Hansen
- The University of Iowa Cochlear Implant Clinical Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Iowa Carver College of Medicine, Iowa City, IA United States
| | - Camille C Dunn
- The University of Iowa Cochlear Implant Clinical Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Iowa Carver College of Medicine, Iowa City, IA United States
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Abstract
Cochlear implants have been the most successful neural prosthesis, with one million users globally. Researchers used the source-filter model and speech vocoder to design the modern multi-channel implants, allowing implantees to achieve 70%-80% correct sentence recognition in quiet, on average. Researchers also used the cochlear implant to help understand basic mechanisms underlying loudness, pitch, and cortical plasticity. While front-end processing advances improved speech recognition in noise, the unilateral implant speech recognition in quiet has plateaued since the early 1990s. This lack of progress calls for action on re-designing the cochlear stimulating interface and collaboration with the general neurotechnology community.
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Affiliation(s)
- Fan-Gang Zeng
- Departments of Anatomy and Neurobiology, Biomedical Engineering, Cognitive Sciences, Otolaryngology-Head and Neck Surgery and Center for Hearing Research, University of California, 110 Medical Sciences E, Irvine, California 92697, USA
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Computed-Tomography Estimates of Interaural Mismatch in Insertion Depth and Scalar Location in Bilateral Cochlear-Implant Users. Otol Neurotol 2022; 43:666-675. [PMID: 35761459 DOI: 10.1097/mao.0000000000003538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
HYPOTHESIS Bilateral cochlear-implant (BI-CI) users will have a range of interaural insertion-depth mismatch because of different array placement or characteristics. Mismatch will be larger for electrodes located near the apex or outside scala tympani, or for arrays that are a mix of precurved and straight types. BACKGROUND Brainstem superior olivary-complex neurons are exquisitely sensitive to interaural-difference cues for sound localization. Because these neurons rely on interaurally place-of-stimulation-matched inputs, interaural insertion-depth or scalar-location differences for BI-CI users could cause interaural place-of-stimulation mismatch that impairs binaural abilities. METHODS Insertion depths and scalar locations were calculated from temporal-bone computed-tomography scans for 107 BI-CI users (27 Advanced Bionics, 62 Cochlear, 18 MED-EL). RESULTS Median interaural insertion-depth mismatch was 23.4 degrees or 1.3 mm. Mismatch in the estimated clinically relevant range expected to impair binaural processing (>75 degrees or 3 mm) occurred for 13 to 19% of electrode pairs overall, and for at least three electrode pairs for 23 to 37% of subjects. There was a significant three-way interaction between insertion depth, scalar location, and array type. Interaural insertion-depth mismatch was largest for apical electrodes, for electrode pairs in two different scala, and for arrays that were both-precurved. CONCLUSION Average BI-CI interaural insertion-depth mismatch was small; however, large interaural insertion-depth mismatch-with the potential to degrade spatial hearing-occurred frequently enough to warrant attention. For new BICI users, improved surgical techniques to avoid interaural insertion-depth and scalar mismatch are recommended. For existing BI-CI users with interaural insertion-depth mismatch, interaural alignment of clinical frequency tables might reduce negative spatial-hearing consequences.
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Dillon MT, O'Connell BP, Canfarotta MW, Buss E, Hopfinger J. Effect of Place-Based Versus Default Mapping Procedures on Masked Speech Recognition: Simulations of Cochlear Implant Alone and Electric-Acoustic Stimulation. Am J Audiol 2022; 31:322-337. [PMID: 35394798 DOI: 10.1044/2022_aja-21-00123] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Cochlear implant (CI) recipients demonstrate variable speech recognition when listening with a CI-alone or electric-acoustic stimulation (EAS) device, which may be due in part to electric frequency-to-place mismatches created by the default mapping procedures. Performance may be improved if the filter frequencies are aligned with the cochlear place frequencies, known as place-based mapping. Performance with default maps versus an experimental place-based map was compared for participants with normal hearing when listening to CI-alone or EAS simulations to observe potential outcomes prior to initiating an investigation with CI recipients. METHOD A noise vocoder simulated CI-alone and EAS devices, mapped with default or place-based procedures. The simulations were based on an actual 24-mm electrode array recipient, whose insertion angles for each electrode contact were used to estimate the respective cochlear place frequency. The default maps used the filter frequencies assigned by the clinical software. The filter frequencies for the place-based maps aligned with the cochlear place frequencies for individual contacts in the low- to mid-frequency cochlear region. For the EAS simulations, low-frequency acoustic information was filtered to simulate aided low-frequency audibility. Performance was evaluated for the AzBio sentences presented in a 10-talker masker at +5 dB signal-to-noise ratio (SNR), +10 dB SNR, and asymptote. RESULTS Performance was better with the place-based maps as compared with the default maps for both CI-alone and EAS simulations. For instance, median performance at +10 dB SNR for the CI-alone simulation was 57% correct for the place-based map and 20% for the default map. For the EAS simulation, those values were 59% and 37% correct. Adding acoustic low-frequency information resulted in a similar benefit for both maps. CONCLUSIONS Reducing frequency-to-place mismatches, such as with the experimental place-based mapping procedure, produces a greater benefit in speech recognition than maximizing bandwidth for CI-alone and EAS simulations. Ongoing work is evaluating the initial and long-term performance benefits in CI-alone and EAS users. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.19529053.
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Affiliation(s)
- Margaret T. Dillon
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
- Division of Speech and Hearing Sciences, Department of Allied Health Sciences, University of North Carolina at Chapel Hill
| | - Brendan P. O'Connell
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - Michael W. Canfarotta
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - Emily Buss
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - Joseph Hopfinger
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill
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Dorman MF, Natale SC, Noble JH, Zeitler DM. Upward Shifts in the Internal Representation of Frequency Can Persist Over a 3-Year Period for Cochlear Implant Patients Fit With a Relatively Short Electrode Array. Front Hum Neurosci 2022; 16:863891. [PMID: 35399353 PMCID: PMC8990937 DOI: 10.3389/fnhum.2022.863891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 02/28/2022] [Indexed: 11/16/2022] Open
Abstract
Patients fit with cochlear implants (CIs) commonly indicate at the time of device fitting and for some time after, that the speech signal sounds abnormal. A high pitch or timbre is one component of the abnormal percept. In this project, our aim was to determine whether a number of years of CI use reduced perceived upshifts in frequency spectrum and/or voice fundamental frequency. The participants were five individuals who were deaf in one ear and who had normal hearing in the other ear. The deafened ears had been implanted with a 18.5 mm electrode array which resulted in signal input frequencies being directed to locations in the spiral ganglion (SG) that were between one and two octaves higher than the input frequencies. The patients judged the similarity of a clean signal (a male-voice sentence) presented to their implanted ear and candidate, implant-like, signals presented to their normal-hearing (NH) ear. Matches to implant sound quality were obtained, on average, at 8 months after device activation (see section “Time 1”) and at 35 months after activation (see section “Time 2”). At Time 1, the matches to CI sound quality were characterized, most generally, by upshifts in the frequency spectrum and in voice pitch. At Time 2, for four of the five patients, frequency spectrum values remained elevated. For all five patients F0 values remained elevated. Overall, the data offer little support for the proposition that, for patients fit with shorter electrode arrays, cortical plasticity nudges the cortical representation of the CI voice toward more normal, or less upshifted, frequency values between 8 and 35 months after device activation. Cortical plasticity may be limited when there are large differences between frequencies in the input signal and the locations in the SG stimulated by those frequencies.
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Affiliation(s)
- Michael F Dorman
- College of Health Solutions, Speech and Hearing Science, Arizona State University, Tempe, AZ, United States
| | - Sarah C Natale
- College of Health Solutions, Speech and Hearing Science, Arizona State University, Tempe, AZ, United States
| | - Jack H Noble
- Department of Electrical Engineering & Computer Science, Vanderbilt University, Nashville, TN, United States
| | - Daniel M Zeitler
- Otolaryngology, Virginia Mason Medical Center, Seattle, WA, United States
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Canfarotta MW, Dillon MT, Brown KD, Pillsbury HC, Dedmon MM, O'Connell BP. Insertion Depth and Cochlear Implant Speech Recognition Outcomes: A Comparative Study of 28- and 31.5-mm Lateral Wall Arrays. Otol Neurotol 2022; 43:183-189. [PMID: 34772886 PMCID: PMC8752482 DOI: 10.1097/mao.0000000000003416] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES 1) To compare speech recognition outcomes between cochlear implant (CI) recipients of 28- and 31.5-mm lateral wall electrode arrays, and 2) to characterize the relationship between angular insertion depth (AID) and speech recognition. STUDY DESIGN Retrospective review. SETTING Tertiary academic referral center. PATIENTS Seventy-five adult CI recipients of fully inserted 28-mm (n = 28) or 31.5-mm (n = 47) lateral wall arrays listening with a CI-alone device. INTERVENTIONS Cochlear implantation with postoperative computed tomography. MAIN OUTCOME MEASURES Consonant-nucleus-consonant (CNC) word recognition assessed with the CI-alone at 12 months postactivation. RESULTS The mean AID of the most apical electrode contact for the 31.5-mm array recipients was significantly deeper than the 28-mm array recipients (628° vs 571°, p < 0.001). Following 12 months of listening experience, mean CNC word scores were significantly better for recipients of 31.5-mm arrays compared with those implanted with 28-mm arrays (59.5% vs 48.3%, p = 0.004; Cohen's d = 0.70; 95% CI [0.22, 1.18]). There was a significant positive correlation between AID and CNC word scores (r = 0.372, p = 0.001), with a plateau in performance observed around 600°. CONCLUSIONS Cochlear implant recipients implanted with a 31.5-mm array experienced better speech recognition than those with a 28-mm array at 12 months postactivation. Deeper insertion of a lateral wall array appears to confer speech recognition benefit up to ∼600°, with a plateau in performance observed thereafter. These data provide preliminary evidence of the insertion depth necessary to optimize speech recognition outcomes for lateral wall electrode arrays among CI-alone users.
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Affiliation(s)
- Michael W Canfarotta
- Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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16
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Aljazeeri I, Hamed N, Abdelsamad Y, Sharif T, Al-Momani M, Hagr A. Anatomy-Based Frequency Allocation in Cochlear Implantation: The Importance of Cochlear Coverage. Laryngoscope 2021; 132:2224-2231. [PMID: 34967457 DOI: 10.1002/lary.30004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 12/09/2021] [Accepted: 12/17/2021] [Indexed: 11/08/2022]
Abstract
OBJECTIVES/HYPOTHESIS This study aimed to compare the predicted anatomy-based frequency allocation of cochlear implant electrodes with the default standard frequencies. STUDY DESIGN Retrospective study. METHODS A retrospective analysis was performed using computed tomography (CT) images of patients who received cochlear implants at a tertiary referral center. Patients were excluded if they had any congenital or acquired cochlear anatomical anomalies. The CT images of the patients were uploaded to the surgical planning software. Two independent reviewers allocated the anatomical parameters of the cochlea. The software then used these parameters to calculate the frequency allocation for each electrode according to the type of electrode and the length of the organ of Corti (OC) in each patient. These anatomy-based frequency allocations were compared with the default frequency settings. MAIN OUTCOME MEASURE Frequency-to-place mismatch in semitones. RESULTS A total of 169 implanted ears in 102 patients were included in this study. The readings of the two reviewers were homogenous, with a Cronbach's alpha of 0.98. The mean anatomy-based frequency allocation was 487.3 ± 202.9 Hz in electrode 1; 9,298.6 ± 490.6 Hz in electrode 12. The anatomy-based frequency allocations were found to be significantly higher than the frequencies of the default frequencies for each corresponding electrode (one-sample t-test, P < .001). The frequency-to-place mismatch was negatively correlated with cochlear coverage and positively correlated with the cochlear duct length (Pearson correlation > 0.65, P < .003). CONCLUSIONS The anatomy-based frequency allocation of each electrode is significantly different from the default frequency setting. This frequency-to-place mismatch was affected mainly by the cochlear coverage. LEVEL OF EVIDENCE 3 Laryngoscope, 2021.
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Affiliation(s)
- Isra Aljazeeri
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University Medical City (KSUMC), King Saud University, Riyadh, Saudi Arabia.,Aljaber Ophthalmology and Otolaryngology Specialized Hospital, Ministry of Health, Ahsa, Saudi Arabia
| | - Nezar Hamed
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University Medical City (KSUMC), King Saud University, Riyadh, Saudi Arabia
| | | | - Tahir Sharif
- Research Department, MED-EL GmbH, Riyadh, Saudi Arabia
| | - Murad Al-Momani
- ENT Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Abdulrahman Hagr
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University Medical City (KSUMC), King Saud University, Riyadh, Saudi Arabia
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17
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Bernstein JGW, Jensen KK, Stakhovskaya OA, Noble JH, Hoa M, Kim HJ, Shih R, Kolberg E, Cleary M, Goupell MJ. Interaural Place-of-Stimulation Mismatch Estimates Using CT Scans and Binaural Perception, But Not Pitch, Are Consistent in Cochlear-Implant Users. J Neurosci 2021; 41:10161-10178. [PMID: 34725189 PMCID: PMC8660045 DOI: 10.1523/jneurosci.0359-21.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 08/23/2021] [Accepted: 10/01/2021] [Indexed: 11/21/2022] Open
Abstract
Bilateral cochlear implants (BI-CIs) or a CI for single-sided deafness (SSD-CI; one normally functioning acoustic ear) can partially restore spatial-hearing abilities, including sound localization and speech understanding in noise. For these populations, however, interaural place-of-stimulation mismatch can occur and thus diminish binaural sensitivity that relies on interaurally frequency-matched neurons. This study examined whether plasticity-reorganization of central neural pathways over time-can compensate for peripheral interaural place mismatch. We hypothesized differential plasticity across two systems: none for binaural processing but adaptation for pitch perception toward frequencies delivered by the specific electrodes. Interaural place mismatch was evaluated in 19 BI-CI and 23 SSD-CI human subjects (both sexes) using binaural processing (interaural-time-difference discrimination with simultaneous bilateral stimulation), pitch perception (pitch ranking for single electrodes or acoustic tones with sequential bilateral stimulation), and physical electrode-location estimates from computed-tomography (CT) scans. On average, CT scans revealed relatively little BI-CI interaural place mismatch (26° insertion-angle mismatch) but a relatively large SSD-CI mismatch, particularly at low frequencies (166° for an electrode tuned to 300 Hz, decreasing to 14° at 7000 Hz). For BI-CI subjects, the three metrics were in agreement because there was little mismatch. For SSD-CI subjects, binaural and CT measurements were in agreement, suggesting little binaural-system plasticity induced by mismatch. The pitch measurements disagreed with binaural and CT measurements, suggesting place-pitch plasticity or a procedural bias. These results suggest that reducing interaural place mismatch and potentially improving binaural processing by reprogramming the CI frequency allocation would be better done using CT-scan than pitch information.SIGNIFICANCE STATEMENT Electrode-array placement for cochlear implants (bionic prostheses that partially restore hearing) does not explicitly align neural representations of frequency information. The resulting interaural place-of-stimulation mismatch can diminish spatial-hearing abilities. In this study, adults with two cochlear implants showed reasonable interaural alignment, whereas those with one cochlear implant but normal hearing in the other ear often showed mismatch. In cases of mismatch, binaural sensitivity was best when the same cochlear locations were stimulated in both ears, suggesting that binaural brainstem pathways do not experience plasticity to compensate for mismatch. In contrast, interaurally pitch-matched electrodes deviated from cochlear-location estimates and did not optimize binaural sensitivity. Clinical correction of interaural place mismatch using binaural or computed-tomography (but not pitch) information may improve spatial-hearing benefits.
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Affiliation(s)
- Joshua G W Bernstein
- National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, Maryland 20889
| | - Kenneth K Jensen
- National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, Maryland 20889
| | - Olga A Stakhovskaya
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742
| | - Jack H Noble
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37232
| | - Michael Hoa
- Department of Otolaryngology Head and Neck Surgery, Georgetown University Medical Center, Washington, DC 20057
| | - H Jeffery Kim
- Department of Otolaryngology Head and Neck Surgery, Georgetown University Medical Center, Washington, DC 20057
| | - Robert Shih
- Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Maryland 20889
| | - Elizabeth Kolberg
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742
| | - Miranda Cleary
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742
| | - Matthew J Goupell
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742
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18
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Carlyon RP, Goehring T. Cochlear Implant Research and Development in the Twenty-first Century: A Critical Update. J Assoc Res Otolaryngol 2021; 22:481-508. [PMID: 34432222 PMCID: PMC8476711 DOI: 10.1007/s10162-021-00811-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 08/02/2021] [Indexed: 12/22/2022] Open
Abstract
Cochlear implants (CIs) are the world's most successful sensory prosthesis and have been the subject of intense research and development in recent decades. We critically review the progress in CI research, and its success in improving patient outcomes, from the turn of the century to the present day. The review focuses on the processing, stimulation, and audiological methods that have been used to try to improve speech perception by human CI listeners, and on fundamental new insights in the response of the auditory system to electrical stimulation. The introduction of directional microphones and of new noise reduction and pre-processing algorithms has produced robust and sometimes substantial improvements. Novel speech-processing algorithms, the use of current-focusing methods, and individualised (patient-by-patient) deactivation of subsets of electrodes have produced more modest improvements. We argue that incremental advances have and will continue to be made, that collectively these may substantially improve patient outcomes, but that the modest size of each individual advance will require greater attention to experimental design and power. We also briefly discuss the potential and limitations of promising technologies that are currently being developed in animal models, and suggest strategies for researchers to collectively maximise the potential of CIs to improve hearing in a wide range of listening situations.
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Affiliation(s)
- Robert P Carlyon
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK.
| | - Tobias Goehring
- Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
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19
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Cooperman SP, Aaron KA, Fouad A, Tran E, Blevins NH, Fitzgerald MB. Influence of electrode to cochlear duct length ratio on post-operative speech understanding outcomes. Cochlear Implants Int 2021; 23:59-69. [PMID: 34590531 DOI: 10.1080/14670100.2021.1979289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To assess whether the pre-operative electrode to cochlear duct length ratio (ECDLR), is associated with post-operative speech recognition outcomes. STUDY DESIGN A retrospective chart review study. SETTING Tertiary referral center. PATIENTS The study included sixty-one adult CI recipients with a pre-operative computed tomography scan and a speech recognition test 12 months after implantation. INTERVENTIONS The average of two raters' cochlear duct length (CDL) measurements and the length of the recipient's cochlear implant electrode array formed the basis for the electrode-to-cochlear duct length ratio (ECLDR). Speech recognition tests were compared as a function of ECDLR and electrode array length itself. MAIN OUTCOME MEASURES The relationship between ECDLR and percent correct on speech recognition tests. RESULTS A second order polynomial regression relating ECDLR to percent correct on the CNC words speech recognition test was statistically significant, as was a fourth order polynomial regression for the AzBio Quiet test. In contrast, there was no statistically significant relationship between speech recognition scores and electrode array length. CONCLUSIONS ECDLR values can be statistically associated to speech-recognition outcomes. However, these ECDLR values cannot be predicted by the electrode length alone, and must include a measure of CDL.
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Affiliation(s)
- Shayna P Cooperman
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Ksenia A Aaron
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Ayman Fouad
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA.,Otolaryngology Department, Tanta University, Tanta, Egypt
| | - Emma Tran
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Nikolas H Blevins
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Matthew B Fitzgerald
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
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20
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Brown KD, Dillon MT, Park LR. Benefits of Cochlear Implantation in Childhood Unilateral Hearing Loss (CUHL Trial). Laryngoscope 2021; 132 Suppl 6:S1-S18. [PMID: 34542181 PMCID: PMC9293149 DOI: 10.1002/lary.29853] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/29/2021] [Accepted: 08/22/2021] [Indexed: 11/12/2022]
Abstract
Objectives/Hypotheses Children with unilateral sensory hearing loss (UHL) struggle to understand speech in noise and locate the origin of sound and have reduced quality of hearing. This clinical trial will determine the benefits of cochlear implantation in children with UHL. Study Design Prospective clinical trial. Methods Twenty children with at least moderate to profound sensory hearing loss and poor speech perception (word score <30%) in one ear and normal hearing in the contralateral ear participated in a Food and Drug Administration‐approved clinical trial. Subjects were evaluated for speech perception in quiet, speech perception in noise, sound localization, and subjective benefits after implantation. Results CNC word score perception in quiet significantly improved (1% to 50%, P < .0001) by 12 months after activation. Speech perception in noise by BKB‐SIN significantly improved in all three noise configurations; there was a 3.6 dB advantage in head shadow (P < .0001), a 1.6 dB advantage in summation (P = .003), and a 2.5 dB advantage in squelch (P = .0001). Localization improved by 26° at 9 months (P < .0001). Speech, Spatial, and Qualities (SSQ) demonstrated significant improvements in speech (5.2 to 7.4, P = .0012), qualities of hearing (5.9 to 7.5, P = .0056), and spatial hearing (2.7 to 6.6, P < .0001). SSQ subscales associated with binaural hearing were significantly improved, as was listening effort (P = .0082). Subjects demonstrated a non‐significant improvement in fatigue. Conclusions This study demonstrates that children with UHL significantly benefit from cochlear implantation. Level of Evidence Level 3 Laryngoscope, 132:S1–S18, 2022
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Affiliation(s)
- Kevin D Brown
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, North Carolina, U.S.A
| | - Margaret T Dillon
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, North Carolina, U.S.A
| | - Lisa R Park
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, North Carolina, U.S.A
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21
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Oh Y, Reiss LAJ. Binaural Pitch Fusion: Binaural Pitch Averaging in Cochlear Implant Users With Broad Binaural Fusion. Ear Hear 2021; 41:1450-1460. [PMID: 33136622 PMCID: PMC7501189 DOI: 10.1097/aud.0000000000000866] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Individuals who use hearing aids (HAs) or cochlear implants (CIs) can experience broad binaural pitch fusion, such that sounds differing in pitch by as much as 3 to 4 octaves are perceptually integrated across ears. Previously, it was shown in HA users that the fused pitch is a weighted average of the two monaural pitches, ranging from equal weighting to dominance by the lower pitch. The goal of this study was to systematically measure the fused pitches in adult CI users, and determine whether CI users experience similar pitch averaging effects as observed in HA users. DESIGN Twelve adult CI users (Cochlear Ltd, Sydney, Australia) participated in this study: six bimodal CI users, who wear a CI with a contralateral HA, and six bilateral CI users. Stimuli to HA ears were acoustic pure tones, and stimuli to CI ears were biphasic pulse trains delivered to individual electrodes. Fusion ranges, the ranges of frequencies/electrodes in the comparison ear that were fused with a single electrode (electrode 22, 18, 12, or 6) in the reference ear, were measured using simultaneous, dichotic presentation of reference and comparison stimuli in opposite ears, and varying the comparison stimulus. Once the fusion ranges were measured, the fused binaural pitch of a reference-pair stimulus combination was measured by finding a pitch match to monaural comparison stimuli presented to the paired stimulus ear. RESULTS Fusion pitch weighting in CI users varied depending on the pitch difference of the reference-pair stimulus combination, with equal pitch averaging occurring for stimuli closer in pitch and lower pitch dominance occurring for stimuli farther apart in pitch. The averaging region was typically 0.5 to 2.3 octaves around the reference for bimodal CI users and 0.4 to 1.5 octaves for bilateral CI users. In some cases, a bias in the averaging region was observed toward the ear with greater stimulus variability. CONCLUSIONS Fusion pitch weighting effects in CI users were similar to those observed previously in HA users. However, CI users showed greater inter-subject variability in both pitch averaging ranges and bias effects. These findings suggest that binaural pitch averaging could be a common underlying mechanism in hearing-impaired listeners.
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Affiliation(s)
- Yonghee Oh
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, Florida, USA
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Lina A. J. Reiss
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
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22
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Hartling CL, Fowler JR, Stark GN, Glickman B, Eddolls M, Oh Y, Ramsey K, Reiss LAJ. Binaural Pitch Fusion in Children With Normal Hearing, Hearing Aids, and Cochlear Implants. Ear Hear 2021; 41:1545-1559. [PMID: 33136630 PMCID: PMC9014818 DOI: 10.1097/aud.0000000000000874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Binaural pitch fusion is the perceptual integration of stimuli that evoke different pitches between the ears into a single auditory image. Adults who use hearing aids (HAs) or cochlear implants (CIs) often experience abnormally broad binaural pitch fusion, such that sounds differing in pitch by as much as 3 to 4 octaves are fused across ears, leading to spectral averaging and speech perception interference. The main goal of this study was to measure binaural pitch fusion in children with different hearing device combinations and compare results across groups and with adults. A second goal was to examine the relationship of binaural pitch fusion to interaural pitch differences or pitch match range, a measure of sequential pitch discriminability. DESIGN Binaural pitch fusion was measured in children between the ages of 6.1 and 11.1 years with bilateral HAs (n = 9), bimodal CI (n = 10), bilateral CIs (n = 17), as well as normal-hearing (NH) children (n = 21). Depending on device combination, stimuli were pure tones or electric pulse trains delivered to individual electrodes. Fusion ranges were measured using simultaneous, dichotic presentation of reference and comparison stimuli in opposite ears, and varying the comparison stimulus to find the range that fused with the reference stimulus. Interaural pitch match functions were measured using sequential presentation of reference and comparison stimuli, and varying the comparison stimulus to find the pitch match center and range. RESULTS Children with bilateral HAs had significantly broader binaural pitch fusion than children with NH, bimodal CI, or bilateral CIs. Children with NH and bilateral HAs, but not children with bimodal or bilateral CIs, had significantly broader fusion than adults with the same hearing status and device configuration. In children with bilateral CIs, fusion range was correlated with several variables that were also correlated with each other: pure-tone average in the second implanted ear before CI, and duration of prior bilateral HA, bimodal CI, or bilateral CI experience. No relationship was observed between fusion range and pitch match differences or range. CONCLUSIONS The findings suggest that binaural pitch fusion is still developing in this age range and depends on hearing device combination but not on interaural pitch differences or discriminability.
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Affiliation(s)
- Curtis L Hartling
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Jennifer R Fowler
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Gemaine N Stark
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Bess Glickman
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Morgan Eddolls
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Yonghee Oh
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
| | - Katrina Ramsey
- Biostatistics and Design Program, Oregon Health and Science University, Portland, Oregon, USA
| | - Lina A J Reiss
- Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon, USA
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23
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Frequency-to-Place Mismatch: Characterizing Variability and the Influence on Speech Perception Outcomes in Cochlear Implant Recipients. Ear Hear 2021; 41:1349-1361. [PMID: 32205726 DOI: 10.1097/aud.0000000000000864] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The spatial position of a cochlear implant (CI) electrode array affects the spectral cues provided to the recipient. Differences in cochlear size and array length lead to substantial variability in angular insertion depth (AID) across and within array types. For CI-alone users, the variability in AID results in varying degrees of frequency-to-place mismatch between the default electric frequency filters and cochlear place of stimulation. For electric-acoustic stimulation (EAS) users, default electric frequency filters also vary as a function of residual acoustic hearing in the implanted ear. The present study aimed to (1) investigate variability in AID associated with lateral wall arrays, (2) determine the subsequent frequency-to-place mismatch for CI-alone and EAS users mapped with default frequency filters, and (3) examine the relationship between early speech perception for CI-alone users and two aspects of electrode position: frequency-to-place mismatch and angular separation between neighboring contacts, a metric associated with spectral selectivity at the periphery. DESIGN One hundred one adult CI recipients (111 ears) with MED-EL Flex24 (24 mm), Flex28 (28 mm), and FlexSOFT/Standard (31.5 mm) arrays underwent postoperative computed tomography to determine AID. A subsequent comparison was made between AID, predicted spiral ganglion place frequencies, and the default frequency filters for CI-alone (n = 84) and EAS users (n = 27). For CI-alone users with complete insertions who listened with maps fit with the default frequency filters (n = 48), frequency-to-place mismatch was quantified at 1500 Hz and angular separation between neighboring contacts was determined for electrodes in the 1 to 2 kHz region. Multiple linear regression was used to examine how frequency-to-place mismatch and angular separation of contacts influence consonant-nucleus-consonant (CNC) scores through 6 months postactivation. RESULTS For CI recipients with complete insertions (n = 106, 95.5%), the AID (mean ± standard deviation) of the most apical contact was 428° ± 34.3° for Flex24 (n = 11), 558° ± 65.4° for Flex28 (n = 48), and 636° ± 42.9° for FlexSOFT/Standard (n = 47) arrays. For CI-alone users, default frequency filters aligned closely with the spiral ganglion map for deeply inserted lateral wall arrays. For EAS users, default frequency filters produced a range of mismatches; absolute deviations of ≤ 6 semitones occurred in only 37% of cases. Participants with shallow insertions and minimal or no residual hearing experienced the greatest mismatch. For CI-alone users, both smaller frequency-to-place mismatch and greater angular separation between contacts were associated with better CNC scores during the initial 6 months of device use. CONCLUSIONS There is significant variability in frequency-to-place mismatch among CI-alone and EAS users with default frequency filters, even between individuals implanted with the same array. When using default frequency filters, mismatch can be minimized with longer lateral wall arrays and insertion depths that meet the edge frequency associated with residual hearing for CI-alone and EAS users, respectively. Smaller degrees of frequency-to-place mismatch and decreased peripheral masking due to more widely spaced contacts may independently support better speech perception with longer lateral wall arrays in CI-alone users.
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The smaller the frequency-to-place mismatch the better the hearing outcomes in cochlear implant recipients? Eur Arch Otorhinolaryngol 2021; 279:1875-1883. [PMID: 34131770 DOI: 10.1007/s00405-021-06899-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/20/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To investigate the effect of frequency-to-place mismatch, i.e. the mismatch between the tonotopic frequency map in the cochlea and the frequency band that is assigned to an electrode contact of a cochlear implant (CI) at the same cochlear location on speech perception outcomes, using postoperative CT images. STUDY DESIGN Retrospective observational single-centre study. METHODS Retrospective pre- and postoperative clinical CT data of 39 CI recipients with normal cochlear anatomy were analysed in an otological surgical planning software. The tonotopic frequency at each electrode position was estimated using the Greenwood function. For each patient, frequency-to-place mismatch between the tonotopic frequency and the fitted centre frequency for each electrode contact was calculated. The influence of frequency-to-place mismatch on speech perception in noise at 6 and 12 months after CI activation was studied. RESULTS A significant linear correlation was found between the frequency-to-place mismatch and speech perception in noise 6 months after cochlear implantation (p < 0.05). The smaller the frequency-to-place mismatch, the better the initial speech perception in noise results of the CI recipients. The significant effect disappeared after 12 months CI experience. CONCLUSION The study findings support the idea of minimizing the frequency-to-place mismatch in CI recipients in order to pursue better initial speech perception in noise. Further research is needed to investigate the prospect of tonotopic fitting strategies based upon postoperative CT images of the exact locations of the electrode contacts.
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Dillon MT, Canfarotta MW, Buss E, O'Connell BP. Comparison of Speech Recognition With an Organ of Corti Versus Spiral Ganglion Frequency-to-Place Function in Place-Based Mapping of Cochlear Implant and Electric-Acoustic Stimulation Devices. Otol Neurotol 2021; 42:721-725. [PMID: 33625196 PMCID: PMC8935664 DOI: 10.1097/mao.0000000000003070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To compare acute speech recognition with a cochlear implant (CI) alone or electric-acoustic stimulation (EAS) device for place-based maps calculated with an organ of Corti (OC) versus a spiral ganglion (SG) frequency-to-place function. PATIENTS Eleven adult CI recipients of a lateral wall electrode array. INTERVENTION Postoperative imaging was used to derive place-based maps calculated with an OC versus SG function. MAIN OUTCOME MEASURE Phoneme recognition was evaluated at initial activation with consonant-nucleus-consonant (CNC) words presented using an OC versus a SG place-based map. RESULTS For the 9 CI-alone users, there was a nonsignificant trend for better acute phoneme recognition with the SG map (mean 18 RAUs) than the OC map (mean 9 RAUs; p = 0.071, 95% CI [≤-1.2]). When including the 2 EAS users in the analysis, performance was significantly better with the SG map (mean 21 RAUs) than the OC map (mean 7 RAUs; p = 0.019, 95% CI [≤-6.2]). CONCLUSIONS Better phoneme recognition with the SG frequency-to-place function could indicate more natural tonotopic alignment of information compared with the OC place-based map.A prospective, randomized investigation is currently underway to assess longitudinal outcomes with place-based mapping in CI-alone and EAS devices using the SG frequency-to-place function.
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Affiliation(s)
- Margaret T Dillon
- Department of Otolaryngology/Head and Neck Surgery, School of Medicine
- Division of Speech & Hearing, Department of Allied Health Sciences, University of North Carolina at Chapel Hill, North Carolina
| | | | - Emily Buss
- Department of Otolaryngology/Head and Neck Surgery, School of Medicine
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Guinan JJ, Lefler SM, Buchman CA, Goodman SS, Lichtenhan JT. Altered mapping of sound frequency to cochlear place in ears with endolymphatic hydrops provide insight into the pitch anomaly of diplacusis. Sci Rep 2021; 11:10380. [PMID: 34001971 PMCID: PMC8128888 DOI: 10.1038/s41598-021-89902-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/26/2021] [Indexed: 11/22/2022] Open
Abstract
A fundamental property of mammalian hearing is the conversion of sound pressure into a frequency-specific place of maximum vibration along the cochlear length, thereby creating a tonotopic map. The tonotopic map makes possible systematic frequency tuning across auditory-nerve fibers, which enables the brain to use pitch to separate sounds from different environmental sources and process the speech and music that connects us to people and the world. Sometimes a tone has a different pitch in the left and right ears, a perceptual anomaly known as diplacusis. Diplacusis has been attributed to a change in the cochlear frequency-place map, but the hypothesized abnormal cochlear map has never been demonstrated. Here we assess cochlear frequency-place maps in guinea-pig ears with experimentally-induced endolymphatic hydrops, a hallmark of Ménière’s disease. Our findings are consistent with the hypothesis that diplacusis is due to an altered cochlear map. Map changes can lead to altered pitch, but the size of the pitch change is also affected by neural synchrony. Our data show that the cochlear frequency-place map is not fixed but can be altered by endolymphatic hydrops. Map changes should be considered in assessing hearing pathologies and treatments.
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Affiliation(s)
- J J Guinan
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, USA.,Department of Otolaryngology, Harvard Medical School, Boston, MA, USA
| | - S M Lefler
- Department of Otolaryngology, School of Medicine, Washington University St. Louis, Campus Box 8115, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA
| | - C A Buchman
- Department of Otolaryngology, School of Medicine, Washington University St. Louis, Campus Box 8115, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA
| | - S S Goodman
- Department of Communication Sciences and Disorders, University of Iowa, Iowa City, IA, USA
| | - J T Lichtenhan
- Department of Otolaryngology, School of Medicine, Washington University St. Louis, Campus Box 8115, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA.
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Dillon MT, Canfarotta MW, Buss E, Hopfinger J, O'Connell BP. Effectiveness of Place-based Mapping in Electric-Acoustic Stimulation Devices. Otol Neurotol 2021; 42:197-202. [PMID: 33885267 PMCID: PMC8787166 DOI: 10.1097/mao.0000000000002965] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The default mapping procedure for electric-acoustic stimulation (EAS) devices uses the cochlear implant recipient's unaided detection thresholds in the implanted ear to derive the acoustic settings and assign the lowest frequency filter of electric stimulation. Individual differences for speech recognition with EAS may be due to discrepancies between the electric frequency filters of individual electrode contacts and the cochlear place of stimulation, known as a frequency-to-place mismatch. Frequency-to-place mismatch of greater than 1/2 octave has been demonstrated in up to 60% of EAS users. Aligning the electric frequency filters via a place-based mapping procedure using postoperative imaging may improve speech recognition with EAS. METHODS Masked sentence recognition was evaluated for normal-hearing subjects (n = 17) listening with vocoder simulations of EAS, using a place-based map and a default map. Simulation parameters were based on audiometric and imaging data from a representative 24-mm electrode array recipient and EAS user. The place-based map aligned electric frequency filters with the cochlear place frequency, which introduced a gap between the simulated acoustic and electric output. The default map settings were derived from the clinical programming software and provided the full speech frequency range. RESULTS Masked sentence recognition was significantly better for simulated EAS with the place-based map as compared with the default map. CONCLUSION The simulated EAS place-based map supported better performance than the simulated EAS default map. This indicates that individualizing maps may improve performance in EAS users by helping them achieve better asymptotic performance earlier and mitigate the need for acclimatization.
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Affiliation(s)
- Margaret T Dillon
- Department of Otolaryngology/Head and Neck Surgery, School of Medicine
- Division of Speech & Hearing, Department of Allied Health Sciences
| | | | - Emily Buss
- Department of Otolaryngology/Head and Neck Surgery, School of Medicine
| | - Joseph Hopfinger
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, North Carolina
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Jensen KK, Cosentino S, Bernstein JGW, Stakhovskaya OA, Goupell MJ. A Comparison of Place-Pitch-Based Interaural Electrode Matching Methods for Bilateral Cochlear-Implant Users. Trends Hear 2021; 25:2331216521997324. [PMID: 34057382 PMCID: PMC8182630 DOI: 10.1177/2331216521997324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/12/2021] [Accepted: 01/29/2021] [Indexed: 11/16/2022] Open
Abstract
Interaural place-of-stimulation mismatch for bilateral cochlear-implant (BI-CI) listeners is often evaluated using pitch-comparison tasks that can be susceptible to procedural biases. Bias effects were compared for three sequential interaural pitch-comparison tasks in six BI-CI listeners using single-electrode direct stimulation. The reference (right ear) was a single basal, middle, or apical electrode. The comparison electrode (left ear) was chosen from one of three ranges: basal half, full array, or apical half. In Experiment 1 (discrimination), interaural pairs were chosen randomly (method of constant stimuli). In Experiment 2 (ranking), an efficient adaptive procedure rank ordered 3 reference and 6 or 11 comparison electrodes. In Experiment 3 (matching), listeners adjusted the comparison electrode to pitch match the reference. Each experiment was evaluated for testing-range bias (point of subjective equality [PSE] vs. comparison-range midpoint) and reference-electrode slope bias (PSE vs. reference electrode). Discrimination showed large biases for both metrics; matching showed a smaller but significant reference-electrode bias; ranking showed no significant biases in either dimension. Ranking and matching were also evaluated for starting-point bias (PSE vs. adaptive-track starting point), but neither showed significant effects. A response-distribution truncation model explained a nonsignificant bias for ranking but it could not fully explain the observed biases for discrimination or matching. It is concluded that (a) BI-CI interaural pitch comparisons are inconsistent across test methods; (b) biases must be evaluated in more than one dimension before accepting the results as valid; and (c) of the three methods tested, ranking was least susceptible to biases and therefore emerged as the optimal approach.
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Affiliation(s)
- Kenneth K. Jensen
- National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, Maryland, United States
| | - Stefano Cosentino
- Department of Hearing and Speech Sciences, University of Maryland, College Park, United States
| | - Joshua G. W. Bernstein
- National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, Maryland, United States
| | - Olga A. Stakhovskaya
- National Military Audiology and Speech Pathology Center, Walter Reed National Military Medical Center, Bethesda, Maryland, United States
- Department of Hearing and Speech Sciences, University of Maryland, College Park, United States
| | - Matthew J. Goupell
- Department of Hearing and Speech Sciences, University of Maryland, College Park, United States
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Reiss LA. Cochlear implants and other inner ear prostheses: today and tomorrow. CURRENT OPINION IN PHYSIOLOGY 2020; 18:49-55. [PMID: 32905432 DOI: 10.1016/j.cophys.2020.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cochlear implants (CIs) are implantable auditory prostheses designed to restore access to sound in deaf individuals via direct electrical stimulation of the auditory nerve. While CIs have been successful in restoring speech perception to many deaf patients, outcomes are variable and speech recognition in noise remains a problem. This chapter will review the factors underlying this variability, and discuss significant recent innovations to address these issues including neural health preservation, characterization, and regeneration, and other inner ear prostheses. The emerging role of central auditory plasticity will also be discussed. Together, these advances will point to the likely future directions for advancing the next generation of CIs and other inner ear prostheses.
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Affiliation(s)
- Lina Aj Reiss
- Oregon Health & Science University, Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Mailcode NRC04, OHSU, Portland 97239, United States
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Abstract
OBJECTIVES Pitch is poorly perceived by cochlear implant (CI) users. However, as it is not well understood how pitch is encoded with electric stimulation, improving pitch representation with a CI is challenging. Changes in place of stimulation along the cochlea have been described as changes in pitch and can be accurately ranked by CI users. However, it remains unknown if place-pitch can be used to encode musical intervals, which are a necessary attribute of pitch. The objective of these experiments is to determine if place-pitch coding can be used to represent musical intervals with a CI. DESIGN In the first experiment, 10 CI users and 10 normal hearing (NH) controls were tested on their sensitivity to changes in the semitone spacing between each of the notes in the melody "Happy Birthday." The changes were implemented by uniformly expanding or compressing the frequency differences between each note in the melody. The participant's task was to scale how "out-of-tune" the melody was for various semitone spacing distortions. The notes were represented by pure-tones ≥440 Hz to minimize potential useful temporal information from the stimuli. A second experiment replicated the first experiment using single-sided deafened CI users allowing for a within-subject control. A third experiment verified that the CI users who participated in Experiment 1 were each able to determine pitch direction reliably. RESULTS Unlike NH listeners, CI listeners often ranked all distortions of interval spacing similarly in both the first and second experiment, and no effect of interval spacing was detected across CI users. Some participants found distorted interval spacings to be less out-of-tune than the nominally correct interval spacings. However, these patterns were inconsistent across listeners. Although performance was better for the NH listeners, the third experiment demonstrated that the CI listeners were able to reliably identify changes in pitch direction from place-pitch coding. CONCLUSIONS The data suggest that place-pitch intervals are not properly represented through a CI sound processor. Some limited support is found for place-pitch being useful for interval encoding as some participants demonstrated improved ratings for certain interval distortions. Presumably the interval representation for these participants could be improved by a change to the frequencies represented by each electrode. However, as these patterns vary across listeners, there is not a universal correction to frequency representation that will solve this issue. As results are similar for single-sided deafened CI users, the limitations in ratings are likely not limited by an eroded representation of the melody caused by an extended duration of deafness.
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Canfarotta MW, Dillon MT, Buchman CA, Buss E, O'Connell BP, Rooth MA, King ER, Pillsbury HC, Adunka OF, Brown KD. Long-Term Influence of Electrode Array Length on Speech Recognition in Cochlear Implant Users. Laryngoscope 2020; 131:892-897. [PMID: 32738069 DOI: 10.1002/lary.28949] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/17/2020] [Accepted: 06/30/2020] [Indexed: 01/06/2023]
Abstract
OBJECTIVES/HYPOTHESIS Results from a prospective trial demonstrated better speech recognition for cochlear implant (CI) recipients implanted with a long lateral wall electrode array compared to subjects with a short array after 1 year of listening experience. As short array recipients may require an extended adaptation period, this study investigated whether differences in speech recognition continued through 4 years of CI use. STUDY DESIGN Long-term follow-up of a prospective randomized trial. METHODS Subjects were randomized to receive a MED-EL medium (24 mm) or standard (31.5 mm) array. Linear mixed models compared speech recognition between cohorts with word recognition in quiet and sentence recognition in noise at 1, 3, 6, 12, 24, and 48 months postactivation. Postoperative imaging and electric frequency filters were reviewed to assess the influence of frequency-to-place mismatch and angular separation between neighboring contacts, a metric associated with peripheral spectral selectivity. RESULTS Long (31.5 mm) array recipients demonstrated superior speech recognition out to 4 years postactivation. There was a significant effect of angular separation between contacts, with more closely spaced contacts associated with poorer speech recognition. There was no significant effect of mismatch, yet this may have been obscured by changes in frequency filters over time. CONCLUSIONS Conventional MED-EL CI recipients implanted with 31.5-mm arrays experience better speech recognition than 24-mm array recipients, initially and with long-term listening experience. The benefit conferred by longer arrays in the present cohort can be partially attributed to more widely spaced electrode contacts, presumably a result of reduced channel interaction. LEVEL OF EVIDENCE 2 Laryngoscope, 131:892-897, 2021.
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Affiliation(s)
- Michael W Canfarotta
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
| | - Margaret T Dillon
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
| | - Craig A Buchman
- Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Emily Buss
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
| | - Brendan P O'Connell
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
| | - Meredith A Rooth
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
| | - English R King
- Department of Audiology, University of North Carolina Health Care, Chapel Hill, North Carolina, U.S.A
| | - Harold C Pillsbury
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
| | - Oliver F Adunka
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, U.S.A
| | - Kevin D Brown
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, U.S.A
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Karoui C, James C, Barone P, Bakhos D, Marx M, Macherey O. Searching for the Sound of a Cochlear Implant: Evaluation of Different Vocoder Parameters by Cochlear Implant Users With Single-Sided Deafness. Trends Hear 2020; 23:2331216519866029. [PMID: 31533581 PMCID: PMC6753516 DOI: 10.1177/2331216519866029] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cochlear implantation in subjects with single-sided deafness (SSD) offers a unique opportunity to directly compare the percepts evoked by a cochlear implant (CI) with those evoked acoustically. Here, nine SSD-CI users performed a forced-choice task evaluating the similarity of speech processed by their CI with speech processed by several vocoders presented to their healthy ear. In each trial, subjects heard two intervals: their CI followed by a certain vocoder in Interval 1 and their CI followed by a different vocoder in Interval 2. The vocoders differed either (i) in carrier type-(sinusoidal [SINE], bandfiltered noise [NOISE], and pulse-spreading harmonic complex) or (ii) in frequency mismatch between the analysis and synthesis frequency ranges-(no mismatch, and two frequency-mismatched conditions of 2 and 4 equivalent rectangular bandwidths [ERBs]). Subjects had to state in which of the two intervals the CI and vocoder sounds were more similar. Despite a large intersubject variability, the PSHC vocoder was judged significantly more similar to the CI than SINE or NOISE vocoders. Furthermore, the No-mismatch and 2-ERB mismatch vocoders were judged significantly more similar to the CI than the 4-ERB mismatch vocoder. The mismatch data were also interpreted by comparing spiral ganglion characteristic frequencies with electrode contact positions determined from postoperative computed tomography scans. Only one subject demonstrated a pattern of preference consistent with adaptation to the CI sound processor frequency-to-electrode allocation table and two subjects showed possible partial adaptation. Those subjects with adaptation patterns presented overall small and consistent frequency mismatches across their electrode arrays.
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Affiliation(s)
- Chadlia Karoui
- Centre de Recherche Cerveau et Cognition, Toulouse, France.,Cochlear France SAS, Toulouse, France
| | - Chris James
- Cochlear France SAS, Toulouse, France.,Department of Otology-Neurotology and Skull Base Surgery, Purpan University Hospital, Toulouse, France
| | - Pascal Barone
- Centre de Recherche Cerveau et Cognition, Toulouse, France
| | - David Bakhos
- Université François-Rabelais de Tours, CHRU de Tours, France.,Ear Nose and Throat department, CHUR de Tours, Tours, France
| | - Mathieu Marx
- Centre de Recherche Cerveau et Cognition, Toulouse, France.,Department of Otology-Neurotology and Skull Base Surgery, Purpan University Hospital, Toulouse, France
| | - Olivier Macherey
- Aix Marseille University, CNRS, Centrale Marseille, LMA, Marseille, France
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Dorman MF, Natale SC, Baxter L, Zeitler DM, Carlson ML, Lorens A, Skarzynski H, Peters JPM, Torres JH, Noble JH. Approximations to the Voice of a Cochlear Implant: Explorations With Single-Sided Deaf Listeners. Trends Hear 2020; 24:2331216520920079. [PMID: 32339072 PMCID: PMC7225791 DOI: 10.1177/2331216520920079] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/23/2020] [Accepted: 03/27/2020] [Indexed: 12/14/2022] Open
Abstract
Fourteen single-sided deaf listeners fit with an MED-EL cochlear implant (CI) judged the similarity of clean signals presented to their CI and modified signals presented to their normal-hearing ear. The signals to the normal-hearing ear were created by (a) filtering, (b) spectral smearing, (c) changing overall fundamental frequency (F0), (d) F0 contour flattening, (e) changing formant frequencies, (f) altering resonances and ring times to create a metallic sound quality, (g) using a noise vocoder, or (h) using a sine vocoder. The operations could be used singly or in any combination. On a scale of 1 to 10 where 10 was a complete match to the sound of the CI, the mean match score was 8.8. Over half of the matches were 9.0 or higher. The most common alterations to a clean signal were band-pass or low-pass filtering, spectral peak smearing, and F0 contour flattening. On average, 3.4 operations were used to create a match. Upshifts in formant frequencies were implemented most often for electrode insertion angles less than approximately 500°. A relatively small set of operations can produce signals that approximate the sound of the MED-EL CI. There are large individual differences in the combination of operations needed. The sound files in Supplemental Material approximate the sound of the MED-EL CI for patients fit with 28-mm electrode arrays.
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Affiliation(s)
- Michael F. Dorman
- Speech and Hearing Science, College of Health Solutions, Arizona State University
| | - Sarah Cook Natale
- Speech and Hearing Science, College of Health Solutions, Arizona State University
| | - Leslie Baxter
- Department of Clinical Neuropsychology, Mayo Clinic Arizona
| | - Daniel M. Zeitler
- Department of Otolaryngology/Head-Neck Surgery, Virginia Mason Medical Center
| | - Matthew L. Carlson
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, United States
| | - Artur Lorens
- World Hearing Centre, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Henryk Skarzynski
- World Hearing Centre, Institute of Physiology and Pathology of Hearing, Warsaw, Poland
| | - Jeroen P. M. Peters
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht
| | | | - Jack H. Noble
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee, United States
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Glennon E, Svirsky MA, Froemke RC. Auditory cortical plasticity in cochlear implant users. Curr Opin Neurobiol 2019; 60:108-114. [PMID: 31864104 DOI: 10.1016/j.conb.2019.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/26/2019] [Accepted: 11/08/2019] [Indexed: 12/31/2022]
Abstract
Cochlear implants are one of the most successful neuroprosthetic devices that have been developed to date. Profoundly deaf patients can achieve speech perception after complete loss of sensory input. Despite the improvements many patients experience, there is still a large degree of outcome variability. It has been proposed that central plasticity may be a major factor in the different levels of benefit that patients experience. However, the neural mechanisms of how plasticity impacts cochlear implant learning and the degree of plasticity's influence remain unknown. Here, we review the human and animal research on three of the main ways that central plasticity affects cochlear implant outcomes.
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Affiliation(s)
- Erin Glennon
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, USA; Neuroscience Institute, New York University School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY, USA; Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Mario A Svirsky
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, USA; Neuroscience Institute, New York University School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY, USA; Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.
| | - Robert C Froemke
- Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, USA; Neuroscience Institute, New York University School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY, USA; Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA; Center for Neural Science, New York University, New York, NY, USA; Howard Hughes Medical Institute Faculty Scholar, USA.
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Adel Y, Nagel S, Weissgerber T, Baumann U, Macherey O. Pitch Matching in Cochlear Implant Users With Single-Sided Deafness: Effects of Electrode Position and Acoustic Stimulus Type. Front Neurosci 2019; 13:1119. [PMID: 31736684 PMCID: PMC6839387 DOI: 10.3389/fnins.2019.01119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 10/03/2019] [Indexed: 01/27/2023] Open
Abstract
Previous studies in patients with single-sided deafness (SSD) have reported results of pitch comparisons between electric stimulation of their cochlear implant (CI) and acoustic stimulation presented to their near-normal hearing contralateral ear. These comparisons typically used sinusoids, although the percept elicited by electric stimulation may be closer to a wideband stimulus. Furthermore, it has been shown that pitch comparisons between sounds with different timbres is a difficult task and subjected to various types of range biases. The present study aims to introduce a method to minimize non-sensory biases, and to investigate the effect of different acoustic stimulus types on the frequency and variability of the electric-acoustic pitch matches. Pitch matches were collected from 13 CI users with SSD using the binary search procedure. Electric stimulation was presented at either an apical or a middle electrode position, at a rate of 800 pps. Acoustic stimulus types were sinusoids (SINE), 1/3-octave wide narrow bands of Gaussian noises (NBN), or 1/3-octave wide pulse spreading harmonic complexes (PSHC). On the one hand, NBN and PSHC are presumed to better mimic the spread of excitation produced by a single-electrode stimulation than SINE. On the other hand, SINE and PSHC contain less inherent fluctuations than NBN and may therefore provide a temporal pattern closer to that produced by a constant-amplitude electric pulse train. Analysis of mean pitch match variance showed no differences between stimulus types. However, mean pitch matches showed effects of electrode position and stimulus type, with the middle electrode always matched to a higher frequency than the apical one (p < 0.001), and significantly higher across-subject pitch matches for PSHC compared with SINE (p = 0.017). Mean pitch matches for all stimulus types were better predicted by place-dependent characteristic frequencies (CFs) based on an organ of Corti map compared with a spiral ganglion map. CF predictions were closest to pitch matches with SINE for the apical electrode position, and conversely with NBN or PSHC for the middle electrode position. These results provide evidence that the choice of acoustic stimulus type can have a significant effect on electric-acoustic pitch matching.
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Affiliation(s)
- Youssef Adel
- Audiological Acoustics, Department of Otorhinolaryngology, University Hospital Frankfurt, Frankfurt, Germany
| | - Sharon Nagel
- Audiological Acoustics, Department of Otorhinolaryngology, University Hospital Frankfurt, Frankfurt, Germany
| | - Tobias Weissgerber
- Audiological Acoustics, Department of Otorhinolaryngology, University Hospital Frankfurt, Frankfurt, Germany
| | - Uwe Baumann
- Audiological Acoustics, Department of Otorhinolaryngology, University Hospital Frankfurt, Frankfurt, Germany
| | - Olivier Macherey
- Aix-Marseille University, CNRS, Centrale Marseille, LMA, Marseille, France
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Dorman MF, Cook Natale S, Baxter L, Zeitler DM, Carlson ML, Noble JH. Cochlear Place of Stimulation Is One Determinant of Cochlear Implant Sound Quality. Audiol Neurootol 2019; 24:264-269. [PMID: 31661682 PMCID: PMC8091953 DOI: 10.1159/000503217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/05/2019] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Our aim was to determine the effect of acute changes in cochlear place of stimulation on cochlear implant (CI) sound quality. DESIGN In Experiment 1, 5 single-sided deaf (SSD) listeners fitted with a long (28-mm) electrode array were tested. Basal shifts in place of stimulation were implemented by turning off the most apical electrodes and reassigning the filters to more basal electrodes. In Experiment 2, 2 SSD patients fitted with a shorter (16.5-mm) electrode array were tested. Both basal and apical shifts in place of stimulation were implemented. The apical shifts were accomplished by current steering and creating a virtual place of stimulation more apical that that of the most apical electrode. RESULTS Listeners matched basal shifts by shifting, in the normal-hearing ear, the overall spectrum up in frequency and/or increasing voice pitch (F0). Listeners matched apical shifts by shifting down the overall frequency spectrum in the normal-hearing ear. CONCLUSION One factor determining CI voice quality is the location of stimulation along the cochlear partition.
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Affiliation(s)
- Michael F Dorman
- College of Health Solutions, Speech and Hearing Science, Arizona State University, Tempe, Arizona, USA,
| | - Sarah Cook Natale
- College of Health Solutions, Speech and Hearing Science, Arizona State University, Tempe, Arizona, USA
| | - Leslie Baxter
- Clinical Neuropsychology, Mayo Clinic Arizona, Phoenix, Arizona, USA
| | - Daniel M Zeitler
- Otolaryngology/Head-Neck Surgery, Virginia Mason Medical Center, Seattle, Washington, USA
| | - Mathew L Carlson
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Jack H Noble
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee, USA
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Dillon MT, Buss E, Rooth MA, King ER, Pillsbury HC, Brown KD. Low-Frequency Pitch Perception in Cochlear Implant Recipients With Normal Hearing in the Contralateral Ear. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2019; 62:2860-2871. [PMID: 31306588 DOI: 10.1044/2019_jslhr-h-18-0409] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Purpose Three experiments were carried out to evaluate the low-frequency pitch perception of adults with unilateral hearing loss who received a cochlear implant (CI). Method Participants were recruited from a cohort of CI users with unilateral hearing loss and normal hearing in the contralateral ear. First, low-frequency pitch perception was assessed for the 5 most apical electrodes at 1, 3, 6, and 12 months after CI activation using an adaptive pitch-matching task. Participants listened with a coding strategy that presents low-frequency temporal fine structure (TFS) and compared the pitch to that of an acoustic target presented to the normal hearing ear. Next, participants listened with an envelope-only, continuous interleaved sampling strategy. Pitch perception was compared between coding strategies to assess the influence of TFS cues on low-frequency pitch perception. Finally, participants completed a vocal pitch-matching task to corroborate the results obtained with the adaptive pitch-matching task. Results Pitch matches roughly corresponded to electrode center frequencies (CFs) in the CI map. Adaptive pitch matches exceeded the CF for the most apical electrode, an effect that was larger for continuous interleaved sampling than TFS. Vocal pitch matches were variable but correlated with the CF of the 3 most apical electrodes. There was no evidence that pitch matches changed between the 1- and 12-month intervals. Conclusions Relatively accurate and asymptotic pitch perception was observed at the 1-month interval, indicating either very rapid acclimatization or the provision of familiar place and rate cues. Early availability of appropriate pitch cues could have played a role in the early improvements in localization and masked speech recognition previously observed in this cohort. Supplemental Material https://doi.org/10.23641/asha.8862389.
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Affiliation(s)
- Margaret T Dillon
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - Emily Buss
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - Meredith A Rooth
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - English R King
- Department of Audiology, UNC Healthcare, Chapel Hill, NC
| | - Harold C Pillsbury
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
| | - Kevin D Brown
- Department of Otolaryngology/Head & Neck Surgery, University of North Carolina at Chapel Hill
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Zhang F, Underwood G, McGuire K, Liang C, Moore DR, Fu QJ. Frequency change detection and speech perception in cochlear implant users. Hear Res 2019; 379:12-20. [PMID: 31035223 DOI: 10.1016/j.heares.2019.04.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/21/2019] [Accepted: 04/15/2019] [Indexed: 10/27/2022]
Abstract
Dynamic frequency changes in sound provide critical cues for speech perception. Most previous studies examining frequency discrimination in cochlear implant (CI) users have employed behavioral tasks in which target and reference tones (differing in frequency) are presented statically in separate time intervals. Participants are required to identify the target frequency by comparing stimuli across these time intervals. However, perceiving dynamic frequency changes in speech requires detection of within-interval frequency change. This study explored the relationship between detection of within-interval frequency changes and speech perception performance of CI users. Frequency change detection thresholds (FCDTs) were measured in 20 adult CI users using a 3-alternative forced-choice (3AFC) procedure. Stimuli were 1-sec pure tones (base frequencies at 0.25, 1, 4 kHz) with frequency changes occurring 0.5 s after the tone onset. Speech tests were 1) Consonant-Nucleus-Consonant (CNC) monosyllabic word recognition, 2) Arizona Biomedical Sentence Recognition (AzBio) in Quiet, 3) AzBio in Noise (AzBio-N, +10 dB signal-to-noise/SNR ratio), and 4) Digits-in-noise (DIN). Participants' subjective satisfaction with the CI was obtained. Results showed that correlations between FCDTs and speech perception were all statistically significant. The satisfaction level of CI use was not related to FCDTs, after controlling for major demographic factors. DIN speech reception thresholds were significantly correlated to AzBio-N scores. The current findings suggest that the ability to detect within-interval frequency changes may play an important role in speech perception performance of CI users. FCDT and DIN can serve as simple and rapid tests that require no or minimal linguistic background for the prediction of CI speech outcomes.
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Affiliation(s)
- Fawen Zhang
- Department of Communication Sciences and Disorders, University of Cincinnati, Ohio, USA.
| | - Gabrielle Underwood
- Department of Communication Sciences and Disorders, University of Cincinnati, Ohio, USA
| | - Kelli McGuire
- Department of Communication Sciences and Disorders, University of Cincinnati, Ohio, USA
| | - Chun Liang
- Department of Communication Sciences and Disorders, University of Cincinnati, Ohio, USA; Shenzhen Maternity & Child Healthcare Hospital, Shenzhen, China
| | - David R Moore
- Communication Sciences Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Otolaryngology, University of Cincinnati, Ohio, USA
| | - Qian-Jie Fu
- Department of Head and Neck Surgery, University of California, Los Angeles, Los Angeles, CA, USA
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A Randomized Controlled Crossover Study of the Impact of Online Music Training on Pitch and Timbre Perception in Cochlear Implant Users. J Assoc Res Otolaryngol 2019; 20:247-262. [PMID: 30815761 DOI: 10.1007/s10162-018-00704-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 10/17/2018] [Indexed: 10/27/2022] Open
Abstract
Cochlear implant (CI) biomechanical constraints result in impoverished spectral cues and poor frequency resolution, making it difficult for users to perceive pitch and timbre. There is emerging evidence that music training may improve CI-mediated music perception; however, much of the existing studies involve time-intensive and less readily accessible in-person music training paradigms, without rigorous experimental control paradigms. Online resources for auditory rehabilitation remain an untapped potential resource for CI users. Furthermore, establishing immediate value from an acute music training program may encourage CI users to adhere to post-implantation rehabilitation exercises. In this study, we evaluated the impact of an acute online music training program on pitch discrimination and timbre identification. Via a randomized controlled crossover study design, 20 CI users and 21 normal hearing (NH) adults were assigned to one of two arms. Arm-A underwent 1 month of online self-paced music training (intervention) followed by 1 month of audiobook listening (control). Arm-B underwent 1 month of audiobook listening followed by 1 month of music training. Pitch and timbre sensitivity scores were taken across three visits: (1) baseline, (2) after 1 month of intervention, and (3) after 1 month of control. We found that performance improved in pitch discrimination among CI users and NH listeners, with both online music training and audiobook listening. Music training, however, provided slightly greater benefit for instrument identification than audiobook listening. For both tasks, this improvement appears to be related to both fast stimulus learning as well as procedural learning. In conclusion, auditory training (with either acute participation in an online music training program or audiobook listening) may improve performance on untrained tasks of pitch discrimination and timbre identification. These findings demonstrate a potential role for music training in perceptual auditory appraisal of complex stimuli. Furthermore, this study highlights the importance and the need for more tightly controlled training studies in order to accurately evaluate the impact of rehabilitation training protocols on auditory processing.
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Bilateral Cochlear Implants Using Two Electrode Lengths in Infants With Profound Deafness. Otol Neurotol 2019; 40:e267-e276. [PMID: 30741906 DOI: 10.1097/mao.0000000000002124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The goal of this investigation was to determine if a short electrode in one ear and standard electrode in the contralateral ear could be an option for infants with congenital profound deafness to theoretically preserve the structures of the inner ear. Similarities in performance between ears and compared with a control group of infants implanted with bilateral standard electrodes was evaluated. STUDY DESIGN Repeated-measure, single-subject experiment. SETTING University of Iowa-Department of Otolaryngology. PARTICIPANTS Nine infants with congenital profound bilateral sensorineural hearing loss. INTERVENTION(S) Short and standard implants. MAIN OUTCOME MEASURE(S) Early speech perception test (ESP), children's vowel, phonetically balanced-kindergarten (PB-K) word test, and preschool language scales-3 (PLS-3). RESULTS ESP scores showed performance reaching a ceiling effect for the individual short and standard ears and bilaterally. The children's vowel and PB-K word results indicated significant (both p < 0.001) differences between the two ears. Bilateral comparisons to age-matched children with standard bilateral electrodes showed no significant differences (p = 0.321) in performance. Global language performance for six children demonstrated standard scores around 1 standard deviation (SD) of the mean. Two children showed scores below the mean, but can be attributed to inconsistent device usage. Averaged total language scores between groups showed no difference in performance (p = 0.293). CONCLUSIONS The combined use of a short electrode and standard electrode might provide an option for implantation with the goal of preserving the cochlear anatomy. However, further studies are needed to understand why some children have or do not have symmetric performance.
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Downing M. Electrode Designs for Protection of the Delicate Cochlear Structures. J Int Adv Otol 2019; 14:401-403. [PMID: 30644381 DOI: 10.5152/iao.2018.6461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The most recent electrode introductions from Advanced Bionics, the HiFocus™ Mid-Scala and the HiFocus SlimJ arrays, have common design goals intended to provide sufficient access to the necessary frequency range while avoiding intracochlear trauma. The electrode choice, either a pre-curved (mid-scala) array or straight (lateral) array, can be made by the surgeon based on anatomical considerations and/or their preferred surgical approach. Both arrays offer ease of handling, suitability for a round window and cochleostomy based insertion and control of the insertion speed.
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Interaural Pitch-Discrimination Range Effects for Bilateral and Single-Sided-Deafness Cochlear-Implant Users. J Assoc Res Otolaryngol 2019; 20:187-203. [PMID: 30623318 DOI: 10.1007/s10162-018-00707-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/26/2018] [Indexed: 10/27/2022] Open
Abstract
By allowing bilateral access to sound, bilateral cochlear implants (BI-CIs) or unilateral CIs for individuals with single-sided deafness (SSD; i.e., normal or near-normal hearing in one ear) can improve sound localization and speech understanding in noise. Spatial hearing in the horizontal plane is primarily conveyed by interaural time and level differences computed from neurons in the superior olivary complex that receive frequency-matched inputs. Because BI-CIs and SSD-CIs do not necessarily convey frequency-matched information, it is critical to understand how to align the inputs to CI users. Previous studies show that interaural pitch discrimination for SSD-CI listeners is highly susceptible to contextual biases, questioning its utility for establishing interaural frequency alignment. Here, we replicate this finding for SSD-CI listeners and show that these biases also extend to BI-CI listeners. To assess the testing-range bias, three ranges of comparison electrodes (BI-CI) or pure-tone frequencies (SSD-CI) were tested: full range, apical/lower half, or basal/upper half. To assess the reference bias, the reference electrode was either held fixed throughout a testing block or randomly chosen from three electrodes (basal end, middle, or apical end of the array). Results showed no effect of reference electrode randomization, but a large testing range bias; changing the center of the testing-range shifted the pitch match by an average 63 % (BI-CI) or 43 % (SSD-CI) of the change magnitude. This bias diminished pitch-match accuracy, with a change in reference electrode shifting the pitch match only an average 34 % (BI-CI) or 40 % (SSD-CI) of the expected amount. Because these effects extended to the relatively more symmetric BI-CI listeners, the results suggest that the bias cannot be attributed to interaural asymmetry. Unless the range effect can be minimized or accounted for, a pitch-discrimination task will produce interaural place-of-stimulation estimates that are highly influenced by the conditions tested, rather than reflecting a true interaural place-pitch comparison.
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Mathew R, Vickers D, Boyle P, Shaida A, Selvadurai D, Jiang D, Undurraga J. Development of electrophysiological and behavioural measures of electrode discrimination in adult cochlear implant users. Hear Res 2018; 367:74-87. [DOI: 10.1016/j.heares.2018.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 06/20/2018] [Accepted: 07/02/2018] [Indexed: 10/28/2022]
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Yu F, Li H, Zhou X, Tang X, Galvin III JJ, Fu QJ, Yuan W. Effects of Training on Lateralization for Simulations of Cochlear Implants and Single-Sided Deafness. Front Hum Neurosci 2018; 12:287. [PMID: 30065641 PMCID: PMC6056606 DOI: 10.3389/fnhum.2018.00287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/27/2018] [Indexed: 11/13/2022] Open
Abstract
While cochlear implantation has benefitted many patients with single-sided deafness (SSD), there is great variability in cochlear implant (CI) outcomes and binaural performance remains poorer than that of normal-hearing (NH) listeners. Differences in sound quality across ears-temporal fine structure (TFS) information with acoustic hearing vs. coarse spectro-temporal envelope information with electric hearing-may limit integration of acoustic and electric patterns. Binaural performance may also be limited by inter-aural mismatch between the acoustic input frequency and the place of stimulation in the cochlea. SSD CI patients must learn to accommodate these differences between acoustic and electric stimulation to maximize binaural performance. It is possible that training may increase and/or accelerate accommodation and further improve binaural performance. In this study, we evaluated lateralization training in NH subjects listening to broad simulations of SSD CI signal processing. A 16-channel vocoder was used to simulate the coarse spectro-temporal cues available with electric hearing; the degree of inter-aural mismatch was varied by adjusting the simulated insertion depth (SID) to be 25 mm (SID25), 22 mm (SID22) and 19 mm (SID19) from the base of the cochlea. Lateralization was measured using headphones and head-related transfer functions (HRTFs). Baseline lateralization was measured for unprocessed speech (UN) delivered to the left ear to simulate SSD and for binaural performance with the acoustic ear combined with the 16-channel vocoders (UN+SID25, UN+SID22 and UN+SID19). After completing baseline measurements, subjects completed six lateralization training exercises with the UN+SID22 condition, after which performance was re-measured for all baseline conditions. Post-training performance was significantly better than baseline for all conditions (p < 0.05 in all cases), with no significant difference in training benefits among conditions. Given that there was no significant difference between the SSD and the SSD CI conditions before or after training, the results suggest that NH listeners were unable to integrate TFS and coarse spectro-temporal cues across ears for lateralization, and that inter-aural mismatch played a secondary role at best. While lateralization training may benefit SSD CI patients, the training may largely improve spectral analysis with the acoustic ear alone, rather than improve integration of acoustic and electric hearing.
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Affiliation(s)
- Fei Yu
- Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Hai Li
- Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Xiaoqing Zhou
- Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - XiaoLin Tang
- Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | | | - Qian-Jie Fu
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Wei Yuan
- Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing, China
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A preliminary study to identify a neurophysiological correlate of electroacoustic pitch matching in cochlear implant users. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:1162-1165. [PMID: 29060081 DOI: 10.1109/embc.2017.8037036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
One challenge facing postlingually-deafened cochlear implant (CI) users is the frequency mismatch between the incoming acoustic signal and the characteristic frequency of the electrically stimulated neurons. Current CI is an open-loop system and it requires extensive fine-tuning to help users to adapt to this mismatch over time. Electric-acoustic pitch matching in unilateral cochlear implant (CI) participants who has residual hearing in the non-implanted ear had been shown to serve as a useful metric to monitor adaptation process. The goal of this study was to identify a potential neurophysiological correlate to this electroacoustic pitch matching for a possible metric to track the adaptation process of CI users over time and a possible feedback for a closed-loop CI system design. This study utilized a method of presenting electrical and acoustic stimuli that were continuously alternating across ears. The stimuli were either matched or mismatched in pitch. Auditory Evoked Potentials (AEP) were recorded from 10 CI users and 10 normal hearing (NH) participants. For NH participants, an acoustic tone at a fixed frequency was presented in place of electrical stimulation. Results with CI participants indicated that N1 latency decreases when the acoustic frequency of the tone presented in the non-implanted ear increases. More importantly, there was an additional shortening of N1 latency in the pitch matched condition. These two patterns were repeated with NH participants. These results indicate the potential utility of N1 latency as an index of pitch matching in both normal hearing listeners and cochlear implant user.
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Abstract
OBJECTIVES Cochlear-implant (CI) users with single-sided deafness (SSD)-that is, one normal-hearing (NH) ear and one CI ear-can obtain some unmasking benefits when a mixture of target and masking voices is presented to the NH ear and a copy of just the masking voices is presented to the CI ear. NH listeners show similar benefits in a simulation of SSD-CI listening, whereby a mixture of target and masking voices is presented to one ear and a vocoded copy of the masking voices is presented to the opposite ear. However, the magnitude of the benefit for SSD-CI listeners is highly variable across individuals and is on average less than for NH listeners presented with vocoded stimuli. One possible explanation for the limited benefit observed for some SSD-CI users is that temporal and spectral discrepancies between the acoustic and electric ears might interfere with contralateral unmasking. The present study presented vocoder simulations to NH participants to examine the effects of interaural temporal and spectral mismatches on contralateral unmasking. DESIGN Speech-reception performance was measured in a competing-talker paradigm for NH listeners presented with vocoder simulations of SSD-CI listening. In the monaural condition, listeners identified target speech masked by two same-gender interferers, presented to the left ear. In the bilateral condition, the same stimuli were presented to the left ear, but the right ear was presented with a noise-vocoded copy of the interfering voices. This paradigm tested whether listeners could integrate the interfering voices across the ears to better hear the monaural target. Three common distortions inherent in CI processing were introduced to the vocoder processing: spectral shifts, temporal delays, and reduced frequency selectivity. RESULTS In experiment 1, contralateral unmasking (i.e., the benefit from adding the vocoded maskers to the second ear) was impaired by spectral mismatches of four equivalent rectangular bandwidths or greater. This is equivalent to roughly a 3.6-mm mismatch between the cochlear places stimulated in the electric and acoustic ears, which is on the low end of the average expected mismatch for SSD-CI listeners. In experiment 2, performance was negatively affected by a temporal mismatch of 24 ms or greater, but not for mismatches in the 0 to 12 ms range expected for SSD-CI listeners. Experiment 3 showed an interaction between spectral shift and spectral resolution, with less effect of interaural spectral mismatches when the number of vocoder channels was reduced. Experiment 4 applied interaural spectral and temporal mismatches in combination. Performance was best when both frequency and timing were aligned, but in cases where a mismatch was present in one dimension (either frequency or latency), the addition of mismatch in the second dimension did not further disrupt performance. CONCLUSIONS These results emphasize the need for interaural alignment-in timing and especially in frequency-to maximize contralateral unmasking for NH listeners presented with vocoder simulations of SSD-CI listening. Improved processing strategies that reduce mismatch between the electric and acoustic ears of SSD-CI listeners might improve their ability to obtain binaural benefits in multitalker environments.
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Tan CT, Martin BA, Svirsky MA. A potential neurophysiological correlate of electric-acoustic pitch matching in adult cochlear implant users: Pilot data. Cochlear Implants Int 2018; 19:198-209. [PMID: 29508662 DOI: 10.1080/14670100.2018.1442126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The overall goal of this study was to identify an objective physiological correlate of electric-acoustic pitch matching in unilaterally implanted cochlear implant (CI) participants with residual hearing in the non-implanted ear. Electrical and acoustic stimuli were presented in a continuously alternating fashion across ears. The acoustic stimulus and the electrical stimulus were either matched or mismatched in pitch. Auditory evoked potentials were obtained from nine CI users. Results indicated that N1 latency was stimulus-dependent, decreasing when the acoustic frequency of the tone presented to the non-implanted ear was increased. More importantly, there was an additional decrease in N1 latency in the pitch-matched condition. These results indicate the potential utility of N1 latency as an index of pitch matching in CI users.
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Affiliation(s)
- Chin-Tuan Tan
- a Department of Electrical and Computer Engineering, School of Behavioral and Brain Science (Callier Center for Communication Disorders) , University of Texas at Dallas , Richardson , TX , USA.,b Program in Speech-Language-Hearing Sciences and Program in Audiology, Graduate Center , City University of New York , New York , NY , USA
| | - Brett A Martin
- b Program in Speech-Language-Hearing Sciences and Program in Audiology, Graduate Center , City University of New York , New York , NY , USA
| | - Mario A Svirsky
- c Department of Otolaryngology , New York University , New York , NY , USA
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Tan CT, Martin B, Svirsky MA. Pitch Matching between Electrical Stimulation of a Cochlear Implant and Acoustic Stimuli Presented to a Contralateral Ear with Residual Hearing. J Am Acad Audiol 2018; 28:187-199. [PMID: 28277210 DOI: 10.3766/jaaa.15063] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Cochlear implants (CIs) successfully restore hearing in postlingually deaf adults, but in doing so impose a frequency-position function in the cochlea that may differ from the physiological one. PURPOSE The CI-imposed frequency-position function is determined by the frequency allocation table programmed into the listener's speech processor and by the location of the electrode array along the cochlea. To what extent can postlingually deaf CI users successfully adapt to the difference between physiological and CI-imposed frequency-position functions? RESEARCH DESIGN We attempt to answer the question by combining behavioral measures of electroacoustic pitch matching (PM) and measures of electrode location within the cochlea. STUDY SAMPLE The participants in this study were 16 adult CI users with residual hearing who could match the pitch of acoustic pure tones presented to their unimplanted ears to the pitch resulting from stimulation of different CI electrodes. DATA COLLECTION AND ANALYSIS We obtained data for four to eight apical electrodes from 16 participants with CIs (most of whom were long-term users), and estimated electrode insertion angle for 12 of these participants. PM functions in this group were compared with the two frequency-position functions discussed above. RESULTS Taken together, the findings were consistent with the possibility that adaptation to the frequency-position function imposed by CIs does happen, but it is not always complete. CONCLUSIONS Some electrodes continue to be perceived as higher pitched than the acoustic frequencies with which they are associated despite years of listening experience after cochlear implantation.
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Affiliation(s)
- Chin-Tuan Tan
- Department of Otolaryngology, NYU School of Medicine, New York, NY
| | - Brett Martin
- Speech and Hearing Sciences, Graduate Center, City University of New York, New York, NY
| | - Mario A Svirsky
- Department of Otolaryngology, NYU School of Medicine, New York, NY
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Perceptual changes with monopolar and phantom electrode stimulation. Hear Res 2017; 359:64-75. [PMID: 29325874 DOI: 10.1016/j.heares.2017.12.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 12/17/2017] [Accepted: 12/23/2017] [Indexed: 11/21/2022]
Abstract
Phantom electrode (PE) stimulation is achieved by simultaneously stimulating out-of-phase from two adjacent intra-cochlear electrodes with different amplitudes. If the basal electrode stimulates with a smaller amplitude than the apical electrode of the pair, the resulting electrical field is pushed away from the basal electrode producing a lower pitch. There is great interest in using PE stimulation in a processing strategy as it can be used to provide stimulation to regions of the cochlea located more apically than the most apical contact on the electrode array. The result is that even lower pitch sensations can be provided without additional risk of a deeper insertion. However, it is unknown if there are perceptual differences between monopolar (MP) and PE stimulation other than a shift in place pitch. Furthermore, it is unknown if the effect and magnitude of changing from MP to PE stimulation is dependent on electrode location. This study investigates the perceptual differences (including pitch and other sound quality differences) at multiple electrode positions using MP and PE stimulation using both a multidimensional scaling procedure (MDS) and a traditional scaling procedure. 10 Advanced Bionics users reported the perceptual distances between 5 single electrode (typically 1, 3, 5, 7, and 9) stimuli in either MP or PE (σ = 0.5) mode. Subjects were asked to report how perceptually different each pair of stimuli were using any perceived differences except loudness. Subsequently, each stimulus was presented in isolation and subjects scaled how "high" or how "clean" each sounded. Results from the MDS task suggest that perceptual differences between MP and PE stimulation can be explained by a single dimension. The traditional scaling suggests that the single dimension is place pitch. PE stimulation elicits lower pitch perceptions in all cochlear regions. Analysis of Cone Beam Computer Tomography (CBCT) data suggests that PE stimulation may be more effective at the apical part of the cochlea. PE stimulation can be used for new sound coding strategies in order to extend the pitch range for cochlear implant (CI) users without perceptual side effects.
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Eshraghi AA, Ocak E. Cochlear Implant Electrode Choice in Challenging Surgical Cases: Malformation, Residual Hearing, Ossification, or Reimplantation. CURRENT OTORHINOLARYNGOLOGY REPORTS 2017. [DOI: 10.1007/s40136-017-0171-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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