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Cychosz M, Edwards JR, Munson B, Romeo R, Kosie J, Newman RS. The everyday speech environments of preschoolers with and without cochlear implants. JOURNAL OF CHILD LANGUAGE 2024:1-22. [PMID: 38362892 DOI: 10.1017/s0305000924000023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Children who receive cochlear implants develop spoken language on a protracted timescale. The home environment facilitates speech-language development, yet it is relatively unknown how the environment differs between children with cochlear implants and typical hearing. We matched eighteen preschoolers with implants (31-65 months) to two groups of children with typical hearing: by chronological age and hearing age. Each child completed a long-form, naturalistic audio recording of their home environment (appx. 16 hours/child; >730 hours of observation) to measure adult speech input, child vocal productivity, and caregiver-child interaction. Results showed that children with cochlear implants and typical hearing were exposed to and engaged in similar amounts of spoken language with caregivers. However, the home environment did not reflect developmental stages as closely for children with implants, or predict their speech outcomes as strongly. Home-based speech-language interventions should focus on the unique input-outcome relationships for this group of children with hearing loss.
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Cychosz M, Xu K, Fu QJ. Effects of spectral smearing on speech understanding and masking release in simulated bilateral cochlear implants. PLoS One 2023; 18:e0287728. [PMID: 37917727 PMCID: PMC10621938 DOI: 10.1371/journal.pone.0287728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/11/2023] [Indexed: 11/04/2023] Open
Abstract
Differences in spectro-temporal degradation may explain some variability in cochlear implant users' speech outcomes. The present study employs vocoder simulations on listeners with typical hearing to evaluate how differences in degree of channel interaction across ears affects spatial speech recognition. Speech recognition thresholds and spatial release from masking were measured in 16 normal-hearing subjects listening to simulated bilateral cochlear implants. 16-channel sine-vocoded speech simulated limited, broad, or mixed channel interaction, in dichotic and diotic target-masker conditions, across ears. Thresholds were highest with broad channel interaction in both ears but improved when interaction decreased in one ear and again in both ears. Masking release was apparent across conditions. Results from this simulation study on listeners with typical hearing show that channel interaction may impact speech recognition more than masking release, and may have implications for the effects of channel interaction on cochlear implant users' speech recognition outcomes.
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Affiliation(s)
- Margaret Cychosz
- Department of Linguistics, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Kevin Xu
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Qian-Jie Fu
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States of America
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Hu H, Klug J, Dietz M. Simulation of ITD-Dependent Single-Neuron Responses Under Electrical Stimulation and with Amplitude-Modulated Acoustic Stimuli. J Assoc Res Otolaryngol 2022; 23:535-550. [PMID: 35334001 PMCID: PMC9437183 DOI: 10.1007/s10162-021-00823-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 11/03/2021] [Indexed: 11/30/2022] Open
Abstract
Interaural time difference (ITD) sensitivity with cochlear implant stimulation is remarkably similar to envelope ITD sensitivity using conventional acoustic stimulation. This holds true for human perception, as well as for neural response rates recorded in the inferior colliculus of several mammalian species. We hypothesize that robust excitatory-inhibitory (EI) interaction is the dominant mechanism. Therefore, we connected the same single EI-model neuron to either a model of the normal acoustic auditory periphery or to a model of the electrically stimulated auditory nerve. The model captured most features of the experimentally obtained response properties with electric stimulation, such as the shape of rate-ITD functions, the dependence on stimulation level, and the pulse rate or modulation-frequency dependence. Rate-ITD functions with high-rate, amplitude-modulated electric stimuli were very similar to their acoustic counterparts. Responses obtained with unmodulated electric pulse trains most resembled acoustic filtered clicks. The fairly rapid decline of ITD sensitivity at rates above 300 pulses or cycles per second is correctly simulated by the 3.1-ms time constant of the inhibitory post-synaptic conductance. As the model accounts for these basic properties, it is expected to help in understanding and quantifying the binaural hearing abilities with electric stimulation when integrated in bigger simulation frameworks.
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Affiliation(s)
- Hongmei Hu
- Department of Medical Physics and Acoustics and Cluster of Excellence "Hearing4all", University of Oldenburg, 26129, Oldenburg, Germany.
| | - Jonas Klug
- Department of Medical Physics and Acoustics and Cluster of Excellence "Hearing4all", University of Oldenburg, 26129, Oldenburg, Germany
| | - Mathias Dietz
- Department of Medical Physics and Acoustics and Cluster of Excellence "Hearing4all", University of Oldenburg, 26129, Oldenburg, Germany
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Novel Approaches to Measure Spatial Release From Masking in Children With Bilateral Cochlear Implants. Ear Hear 2022; 43:101-114. [PMID: 34133400 PMCID: PMC8671563 DOI: 10.1097/aud.0000000000001080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVES To investigate the role of auditory cues for spatial release from masking (SRM) in children with bilateral cochlear implants (BiCIs) and compare their performance with children with normal hearing (NH). To quantify the contribution to speech intelligibility benefits from individual auditory cues: head shadow, binaural redundancy, and interaural differences; as well as from multiple cues: SRM and binaural squelch. To assess SRM using a novel approach of adaptive target-masker angular separation, which provides a more functionally relevant assessment in realistic complex auditory environments. DESIGN Children fitted with BiCIs (N = 11) and with NH (N = 18) were tested in virtual acoustic space that was simulated using head-related transfer functions measured from individual children with BiCIs behind the ear and from a standard head and torso simulator for all NH children. In experiment I, by comparing speech reception thresholds across 4 test conditions that varied in target-masker spatial separation (colocated versus separated at 180°) and listening conditions (monaural versus binaural/bilateral listening), intelligibility benefits were derived for individual auditory cues for SRM. In experiment II, SRM was quantified using a novel measure to find the minimum angular separation (MAS) between the target and masker to achieve a fixed 20% intelligibility improvement. Target speech was fixed at either +90 or -90° azimuth on the side closer to the better ear (+90° for all NH children) and masker locations were adaptively varied. RESULTS In experiment I, children with BiCIs as a group had smaller intelligibility benefits from head shadow than NH children. No group difference was observed in benefits from binaural redundancy or interaural difference cues. In both groups of children, individuals who gained a larger benefit from interaural differences relied less on monaural head shadow, and vice versa. In experiment II, all children with BiCIs demonstrated measurable MAS thresholds <180° and on average larger than that from NH children. Eight of 11 children with BiCIs and all NH children had a MAS threshold <90°, requiring interaural differences only to gain the target intelligibility benefit; whereas the other 3 children with BiCIs had a MAS between 120° and 137°, requiring monaural head shadow for SRM. CONCLUSIONS When target and maskers were separated at 180° on opposing hemifields, children with BiCIs demonstrated greater intelligibility benefits from head shadow and interaural differences than previous literature showed with a smaller separation. Children with BiCIs demonstrated individual differences in using auditory cues for SRM. From the MAS thresholds, more than half of the children with BiCIs demonstrated robust access to interaural differences without needing additional monaural head shadow for SRM. Both experiments led to the conclusion that individualized fitting strategies in the bilateral devices may be warranted to maximize spatial hearing for children with BiCIs in complex auditory environments.
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Ellen Peng Z, Litovsky RY. The Role of Interaural Differences, Head Shadow, and Binaural Redundancy in Binaural Intelligibility Benefits Among School-Aged Children. Trends Hear 2021; 25:23312165211045313. [PMID: 34609935 PMCID: PMC8642055 DOI: 10.1177/23312165211045313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 11/16/2022] Open
Abstract
In complex listening environments, children can benefit from auditory spatial cues to understand speech in noise. When a spatial separation is introduced between the target and masker and/or listening with two ears versus one ear, children can gain intelligibility benefits with access to one or more auditory cues for unmasking: monaural head shadow, binaural redundancy, and interaural differences. This study systematically quantified the contribution of individual auditory cues in providing binaural speech intelligibility benefits for children with normal hearing between 6 and 15 years old. In virtual auditory space, target speech was presented from + 90° azimuth (i.e., listener's right), and two-talker babble maskers were either co-located (+ 90° azimuth) or separated by 180° (-90° azimuth, listener's left). Testing was conducted over headphones in monaural (i.e., right ear) or binaural (i.e., both ears) conditions. Results showed continuous improvement of speech reception threshold (SRT) between 6 and 15 years old and immature performance at 15 years of age for both SRTs and intelligibility benefits from more than one auditory cue. With early maturation of head shadow, the prolonged maturation of unmasking was likely driven by children's poorer ability to gain full benefits from interaural difference cues. In addition, children demonstrated a trade-off between the benefits from head shadow versus interaural differences, suggesting an important aspect of individual differences in accessing auditory cues for binaural intelligibility benefits during development.
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Affiliation(s)
- Z. Ellen Peng
- Waisman Center, University of
Wisconsin-Madison, Madison, WI, USA
| | - Ruth Y. Litovsky
- Waisman Center, University of
Wisconsin-Madison, Madison, WI, USA
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Misurelli SM, Goupell MJ, Burg EA, Jocewicz R, Kan A, Litovsky RY. Auditory Attention and Spatial Unmasking in Children With Cochlear Implants. Trends Hear 2020; 24:2331216520946983. [PMID: 32812515 PMCID: PMC7446264 DOI: 10.1177/2331216520946983] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The ability to attend to target speech in background noise is an important skill, particularly for children who spend many hours in noisy environments. Intelligibility improves as a result of spatial or binaural unmasking in the free-field for normal-hearing children; however, children who use bilateral cochlear implants (BiCIs) demonstrate little benefit in similar situations. It was hypothesized that poor auditory attention abilities might explain the lack of unmasking observed in children with BiCIs. Target and interferer speech stimuli were presented to either or both ears of BiCI participants via their clinical processors. Speech reception thresholds remained low when the target and interferer were in opposite ears, but they did not show binaural unmasking when the interferer was presented to both ears and the target only to one ear. These results demonstrate that, in the most extreme cases of stimulus separation, children with BiCIs can ignore an interferer and attend to target speech, but there is weak or absent binaural unmasking. It appears that children with BiCIs mostly experience poor encoding of binaural cues rather than deficits in ability to selectively attend to target speech.
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Affiliation(s)
- Sara M Misurelli
- Waisman Center, University of Wisconsin-Madison.,Department of Surgery, Division of Otolaryngology, University of Wisconsin School of Medicine and Public Health
| | | | | | | | - Alan Kan
- Waisman Center, University of Wisconsin-Madison.,School of Engineering, Macquarie University, Sydney, Australia
| | - Ruth Y Litovsky
- Waisman Center, University of Wisconsin-Madison.,Department of Surgery, Division of Otolaryngology, University of Wisconsin School of Medicine and Public Health
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Speech Perception, Dichotic Listening, and Ear Advantage in Simultaneous Bilateral Cochlear Implanted Children. Otol Neurotol 2020; 41:e208-e215. [DOI: 10.1097/mao.0000000000002456] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Bennett EE, Litovsky RY. Sound Localization in Toddlers with Normal Hearing and with Bilateral Cochlear Implants Revealed Through a Novel "Reaching for Sound" Task. J Am Acad Audiol 2019; 31:195-208. [PMID: 31429402 DOI: 10.3766/jaaa.18092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Spatial hearing abilities in children with bilateral cochlear implants (BiCIs) are typically improved when two implants are used compared with a single implant. However, even with BiCIs, spatial hearing is still worse compared to normal-hearing (NH) age-matched children. Here, we focused on children who were younger than three years, hence in their toddler years. Prior research with this age focused on measuring discrimination of sounds from the right versus left. PURPOSE This study measured both discrimination and sound location identification in a nine-alternative forced-choice paradigm using the "reaching for sound" method, whereby children reached for sounding objects as a means of capturing their spatial hearing abilities. RESEARCH DESIGN Discrimination was measured with sounds randomly presented to the left versus right, and loudspeakers at fixed angles ranging from ±60° to ±15°. On a separate task, sound location identification was measured for locations ranging from ±60° in 15° increments. STUDY SAMPLE Thirteen children with BiCIs (27-42 months old) and fifteen age-matched (NH). DATA COLLECTION AND ANALYSIS Discrimination and sound localization were completed for all subjects. For the left-right discrimination task, participants were required to reach a criterion of 4/5 correct trials (80%) at each angular separation prior to beginning the localization task. For sound localization, data was analyzed in two ways. First, percent correct scores were tallied for each participant. Second, for each participant, the root-mean-square-error was calculated to determine the average distance between the response and stimulus, indicative of localization accuracy. RESULTS All BiCI users were able to discriminate left versus right at angles as small as ±15° when listening with two implants; however, performance was significantly worse when listening with a single implant. All NH toddlers also had >80% correct at ±15°. Sound localization results revealed root-mean-square errors averaging 11.15° in NH toddlers. Children in the BiCI group were generally unable to identify source location on this complex task (average error 37.03°). CONCLUSIONS Although some toddlers with BiCIs are able to localize sound in a manner consistent with NH toddlers, for the majority of toddlers with BiCIs, sound localization abilities are still emerging.
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Affiliation(s)
- Erica E Bennett
- Henry Ford Health System, Detroit, MI.,Waisman Center, University of Wisconsin-Madison, Madison, WI
| | - Ruth Y Litovsky
- Waisman Center, University of Wisconsin-Madison, Madison, WI
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Hess CL, Misurelli SM, Litovsky RY. Spatial Release From Masking in 2-Year-Olds With Normal Hearing and With Bilateral Cochlear Implants. Trends Hear 2019; 22:2331216518775567. [PMID: 29761735 PMCID: PMC5956632 DOI: 10.1177/2331216518775567] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
This study evaluated spatial release from masking (SRM) in 2- to 3-year-old children who are deaf and were implanted with bilateral cochlear implants (BiCIs), and in age-matched normal-hearing (NH) toddlers. Here, we examined whether early activation of bilateral hearing has the potential to promote SRM that is similar to age-matched NH children. Listeners were 13 NH toddlers and 13 toddlers with BiCIs, ages 27 to 36 months. Speech reception thresholds (SRTs) were measured for target speech in front (0°) and for competitors that were either Colocated in front (0°) or Separated toward the right (+90°). SRM was computed as the difference between SRTs in the front versus in the asymmetrical condition. Results show that SRTs were higher in the BiCI than NH group in all conditions. Both groups had higher SRTs in the Colocated and Separated conditions compared with Quiet, indicating masking. SRM was significant only in the NH group. In the BiCI group, the group effect of SRM was not significant, likely limited by the small sample size; however, all but two children had SRM values within the NH range. This work shows that to some extent, the ability to use spatial cues for source segregation develops by age 2 to 3 in NH children and is attainable in most of the children in the BiCI group. There is potential for the paradigm used here to be used in clinical settings to evaluate outcomes of bilateral hearing in very young children.
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Thakkar T, Kan A, Jones HG, Litovsky RY. Mixed stimulation rates to improve sensitivity of interaural timing differences in bilateral cochlear implant listeners. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:1428. [PMID: 29604701 PMCID: PMC5851783 DOI: 10.1121/1.5026618] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 02/16/2018] [Accepted: 02/17/2018] [Indexed: 05/29/2023]
Abstract
Normal hearing listeners extract small interaural time differences (ITDs) and interaural level differences (ILDs) to locate sounds and segregate targets from noise. Bilateral cochlear implant listeners show poor sensitivity to ITDs when using clinical processors. This is because common clinical stimulation approaches use high rates [∼1000 pulses per-second (pps)] for each electrode in order to provide good speech representation, but sensitivity to ITDs is best at low rates of stimulation (∼100-300 pps). Mixing rates of stimulation across the array is a potential solution. Here, ITD sensitivity for a number of mixed-rate configurations that were designed to preserve speech envelope cues using high-rate stimulation and spatial hearing using low rate stimulation was examined. Results showed that ITD sensitivity in mixed-rate configurations when only one low rate electrode was included generally yielded ITD thresholds comparable to a configuration with low rates only. Low rate stimulation at basal or middle regions on the electrode array yielded the best sensitivity to ITDs. This work provides critical evidence that supports the use of mixed-rate strategies for improving ITD sensitivity in bilateral cochlear implant users.
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Affiliation(s)
- Tanvi Thakkar
- Binaural Hearing and Speech Laboratory, Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Alan Kan
- Binaural Hearing and Speech Laboratory, Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Heath G Jones
- Binaural Hearing and Speech Laboratory, Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Ruth Y Litovsky
- Binaural Hearing and Speech Laboratory, Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
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11
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Binaural integration: a challenge to overcome for children with hearing loss. Curr Opin Otolaryngol Head Neck Surg 2017; 25:514-519. [DOI: 10.1097/moo.0000000000000413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Ehlers E, Goupell MJ, Zheng Y, Godar SP, Litovsky RY. Binaural sensitivity in children who use bilateral cochlear implants. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:4264. [PMID: 28618809 PMCID: PMC5464955 DOI: 10.1121/1.4983824] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 05/29/2023]
Abstract
Children who are deaf and receive bilateral cochlear implants (BiCIs) perform better on spatial hearing tasks using bilateral rather than unilateral inputs; however, they underperform relative to normal-hearing (NH) peers. This gap in performance is multi-factorial, including the inability of speech processors to reliably deliver binaural cues. Although much is known regarding binaural sensitivity of adults with BiCIs, less is known about how the development of binaural sensitivity in children with BiCIs compared to NH children. Sixteen children (ages 9-17 years) were tested using synchronized research processors. Interaural time differences and interaural level differences (ITDs and ILDs, respectively) were presented to pairs of pitch-matched electrodes. Stimuli were 300-ms, 100-pulses-per-second, constant-amplitude pulse trains. In the first and second experiments, discrimination of interaural cues (either ITDs or ILDs) was measured using a two-interval left/right task. In the third experiment, subjects reported the perceived intracranial position of ITDs and ILDs in a lateralization task. All children demonstrated sensitivity to ILDs, possibly due to monaural level cues. Children who were born deaf had weak or absent sensitivity to ITDs; in contrast, ITD sensitivity was noted in children with previous exposure to acoustic hearing. Therefore, factors such as auditory deprivation, in particular, lack of early exposure to consistent timing differences between the ears, may delay the maturation of binaural circuits and cause insensitivity to binaural differences.
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Affiliation(s)
- Erica Ehlers
- University of Wisconsin-Madison, Waisman Center, 1500 Highland Avenue, Madison, Wisconsin 53705, USA
| | - Matthew J Goupell
- Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742, USA
| | - Yi Zheng
- Beijing Advanced Innovation Center for Future Education, Beijing Normal University, Beijing 100875, China
| | - Shelly P Godar
- University of Wisconsin-Madison, Waisman Center, 1500 Highland Avenue, Madison, Wisconsin 53705, USA
| | - Ruth Y Litovsky
- University of Wisconsin-Madison, Waisman Center, 1500 Highland Avenue, Madison, Wisconsin 53705, USA
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Litovsky RY, Gordon K. Bilateral cochlear implants in children: Effects of auditory experience and deprivation on auditory perception. Hear Res 2016; 338:76-87. [PMID: 26828740 PMCID: PMC5647834 DOI: 10.1016/j.heares.2016.01.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 01/07/2016] [Accepted: 01/11/2016] [Indexed: 11/29/2022]
Abstract
Spatial hearing skills are essential for children as they grow, learn and play. These skills provide critical cues for determining the locations of sources in the environment, and enable segregation of important sounds, such as speech, from background maskers or interferers. Spatial hearing depends on availability of monaural cues and binaural cues. The latter result from integration of inputs arriving at the two ears from sounds that vary in location. The binaural system has exquisite mechanisms for capturing differences between the ears in both time of arrival and intensity. The major cues that are thus referred to as being vital for binaural hearing are: interaural differences in time (ITDs) and interaural differences in levels (ILDs). In children with normal hearing (NH), spatial hearing abilities are fairly well developed by age 4-5 years. In contrast, most children who are deaf and hear through cochlear implants (CIs) do not have an opportunity to experience normal, binaural acoustic hearing early in life. These children may function by having to utilize auditory cues that are degraded with regard to numerous stimulus features. In recent years there has been a notable increase in the number of children receiving bilateral CIs, and evidence suggests that while having two CIs helps them function better than when listening through a single CI, these children generally perform worse than their NH peers. This paper reviews some of the recent work on bilaterally implanted children. The focus is on measures of spatial hearing, including sound localization, release from masking for speech understanding in noise and binaural sensitivity using research processors. Data from behavioral and electrophysiological studies are included, with a focus on the recent work of the authors and their collaborators. The effects of auditory plasticity and deprivation on the emergence of binaural and spatial hearing are discussed along with evidence for reorganized processing from both behavioral and electrophysiological studies. The consequences of both unilateral and bilateral auditory deprivation during development suggest that the relevant set of issues is highly complex with regard to successes and the limitations experienced by children receiving bilateral cochlear implants. This article is part of a Special Issue entitled .
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Affiliation(s)
- Ruth Y Litovsky
- University of Wisconsin-Madison, 1500 Highland Ave, Madison, WI, 53705, United States.
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