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Cychosz M, Winn MB, Goupell MJ. How to vocode: Using channel vocoders for cochlear-implant research. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2024; 155:2407-2437. [PMID: 38568143 PMCID: PMC10994674 DOI: 10.1121/10.0025274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 02/23/2024] [Indexed: 04/05/2024]
Abstract
The channel vocoder has become a useful tool to understand the impact of specific forms of auditory degradation-particularly the spectral and temporal degradation that reflect cochlear-implant processing. Vocoders have many parameters that allow researchers to answer questions about cochlear-implant processing in ways that overcome some logistical complications of controlling for factors in individual cochlear implant users. However, there is such a large variety in the implementation of vocoders that the term "vocoder" is not specific enough to describe the signal processing used in these experiments. Misunderstanding vocoder parameters can result in experimental confounds or unexpected stimulus distortions. This paper highlights the signal processing parameters that should be specified when describing vocoder construction. The paper also provides guidance on how to determine vocoder parameters within perception experiments, given the experimenter's goals and research questions, to avoid common signal processing mistakes. Throughout, we will assume that experimenters are interested in vocoders with the specific goal of better understanding cochlear implants.
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Affiliation(s)
- Margaret Cychosz
- Department of Linguistics, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - Matthew B Winn
- Department of Speech-Language-Hearing Sciences, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Matthew J Goupell
- Department of Hearing and Speech Sciences, University of Maryland, College Park, College Park, Maryland 20742, USA
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Quass GL, Kral A. Tripolar configuration and pulse shape in cochlear implants reduce channel interactions in the temporal domain. Hear Res 2024; 443:108953. [PMID: 38277881 DOI: 10.1016/j.heares.2024.108953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/08/2024] [Accepted: 01/11/2024] [Indexed: 01/28/2024]
Abstract
The present study investigates effects of current focusing and pulse shape on threshold, dynamic range, spread of excitation and channel interaction in the time domain using cochlear implant stimulation. The study was performed on 20 adult guinea pigs using a 6-channel animal cochlear implant, recording was performed in the auditory midbrain using a multielectrode array. After determining the best frequencies for individual recording contacts with acoustic stimulation, the ear was deafened and a cochlear implant was inserted into the cochlea. The position of the implant was controlled by x-ray. Stimulation with biphasic, pseudomonophasic and monophasic stimuli was performed with monopolar, monopolar with common ground, bipolar and tripolar configuration in two sets of experiments, allowing comparison of the effects of the different stimulation strategies on threshold, dynamic range, spread of excitation and channel interaction. Channel interaction was studied in the temporal domain, where two electrodes were activated with pulse trains and phase locking to these pulse trains in the midbrain was quantified. The results documented multifactorial influences on the response properties, with significant interaction between factors. Thresholds increased with increasing current focusing, but decreased with pseudomonophasic and monophasic pulse shapes. The results documented that current focusing, particularly tripolar configuration, effectively reduces channel interaction, but that also pseudomonophasic and monophasic stimulation and phase duration intensity coding reduce channel interactions.
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Affiliation(s)
- Gunnar L Quass
- Institute for AudioNeuroTechnology (VIANNA) & Department of Experimental Otology, Otolaryngology Clinics, Hannover Medical School, Hannover, Germany; Cluster of Excellence "Hearing4All" (EXC 2177), Germany.
| | - Andrej Kral
- Institute for AudioNeuroTechnology (VIANNA) & Department of Experimental Otology, Otolaryngology Clinics, Hannover Medical School, Hannover, Germany; Cluster of Excellence "Hearing4All" (EXC 2177), Germany; Australian Hearing Hub, School of Medicine and Health Sciences, Macquarie University, Sydney, Australia
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Babaoğlu G, Rachman L, Ertürk P, Özkişi Yazgan B, Sennaroğlu G, Gaudrain E, Başkent D. Perception of voice cues in school-age children with hearing aids. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2024; 155:722-741. [PMID: 38284822 DOI: 10.1121/10.0024356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 12/26/2023] [Indexed: 01/30/2024]
Abstract
The just-noticeable differences (JNDs) of the voice cues of voice pitch (F0) and vocal-tract length (VTL) were measured in school-aged children with bilateral hearing aids and children and adults with normal hearing. The JNDs were larger for hearing-aided than normal-hearing children up to the age of 12 for F0 and into adulthood for all ages for VTL. Age was a significant factor for both groups for F0 JNDs, but only for the hearing-aided group for VTL JNDs. Age of maturation was later for F0 than VTL. Individual JNDs of the two groups largely overlapped for F0, but little for VTL. Hearing thresholds (unaided or aided, 500-400 Hz, overlapping with mid-range speech frequencies) did not correlate with the JNDs. However, extended low-frequency hearing thresholds (unaided, 125-250 Hz, overlapping with voice F0 ranges) correlated with the F0 JNDs. Hence, age and hearing status differentially interact with F0 and VTL perception, and VTL perception seems challenging for hearing-aided children. On the other hand, even children with profound hearing loss could do the task, indicating a hearing aid benefit for voice perception. Given the significant age effect and that for F0 the hearing-aided children seem to be catching up with age-typical development, voice cue perception may continue developing in hearing-aided children.
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Affiliation(s)
- Gizem Babaoğlu
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Laura Rachman
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Pınar Ertürk
- Department of Audiology, Health Sciences Institute, Hacettepe University, Ankara, Turkey
| | - Başak Özkişi Yazgan
- Department of Audiology, Health Sciences Institute, Hacettepe University, Ankara, Turkey
| | - Gonca Sennaroğlu
- Department of Audiology, Health Sciences Institute, Hacettepe University, Ankara, Turkey
| | - Etienne Gaudrain
- Lyon Neuroscience Research Center, CNRS UMR5292, Inserm U1028, Université Lyon 1, Lyon, France
| | - Deniz Başkent
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, The Netherlands
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Zekveld AA, Pielage H, Versfeld NJ, Kramer SE. The Influence of Hearing Loss on the Pupil Response to Degraded Speech. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:4083-4099. [PMID: 37699194 DOI: 10.1044/2023_jslhr-23-00093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
PURPOSE Current evidence regarding the influence of hearing loss on the pupil response elicited by speech perception is inconsistent. This might be partially due to confounding effects of age. This study aimed to compare pupil responses in age-matched groups of normal-hearing (NH) and hard of hearing (HH) listeners during listening to speech. METHOD We tested the baseline pupil size and mean and peak pupil dilation response of 17 NH participants (Mage = 46 years; age range: 20-62 years) and 17 HH participants (Mage = 45 years; age range: 20-63 years) who were pairwise matched on age and educational level. Participants performed three speech perception tasks at a 50% intelligibility level: noise-vocoded speech and speech masked with either stationary noise or interfering speech. They also listened to speech presented in quiet. RESULTS Hearing loss was associated with poorer speech perception, except for noise-vocoded speech. In contrast to NH participants, performance of HH participants did not improve across trials for the interfering speech condition, and it decreased for speech in stationary noise. HH participants had a smaller mean pupil dilation in degraded speech conditions compared to NH participants, but not for speech in quiet. They also had a steeper decline in the baseline pupil size across trials. The baseline pupil size was smaller for noise-vocoded speech as compared to the other conditions. The normalized data showed an additional group effect on the baseline pupil response. CONCLUSIONS Hearing loss is associated with a smaller pupil response and steeper decline in baseline pupil size during the perception of degraded speech. This suggests difficulties of the HH participants to sustain their effort investment and performance across the test session.
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Affiliation(s)
- Adriana A Zekveld
- Ear & Hearing Section, Otolaryngology-Head and Neck Surgery, Amsterdam UMC, VU University medical center Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, the Netherlands
| | - Hidde Pielage
- Ear & Hearing Section, Otolaryngology-Head and Neck Surgery, Amsterdam UMC, VU University medical center Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, the Netherlands
| | - Niek J Versfeld
- Ear & Hearing Section, Otolaryngology-Head and Neck Surgery, Amsterdam UMC, VU University medical center Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, the Netherlands
| | - Sophia E Kramer
- Ear & Hearing Section, Otolaryngology-Head and Neck Surgery, Amsterdam UMC, VU University medical center Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, the Netherlands
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Tao DD, Shi B, Galvin JJ, Liu JS, Fu QJ. Frequency detection, frequency discrimination, and spectro-temporal pattern perception in older and younger typically hearing adults. Heliyon 2023; 9:e18922. [PMID: 37583764 PMCID: PMC10424075 DOI: 10.1016/j.heliyon.2023.e18922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 07/14/2023] [Accepted: 08/02/2023] [Indexed: 08/17/2023] Open
Abstract
Elderly adults often experience difficulties in speech understanding, possibly due to age-related deficits in frequency perception. It is unclear whether age-related deficits in frequency perception differ between the apical or basal regions of the cochlea. It is also unclear how aging might differently affect frequency discrimination or detection of a change in frequency within a stimulus. In the present study, pure-tone frequency thresholds were measured in 19 older (61-74 years) and 20 younger (22-28 years) typically hearing adults. Participants were asked to discriminate between reference and probe frequencies or to detect changes in frequency within a probe stimulus. Broadband spectro-temporal pattern perception was also measured using the spectro-temporal modulated ripple test (SMRT). Frequency thresholds were significantly poorer in the basal than in the apical region of the cochlea; the deficit in the basal region was 2 times larger for the older than for the younger group. Frequency thresholds were significantly poorer in the older group, especially in the basal region where frequency detection thresholds were 3.9 times poorer for the older than for the younger group. SMRT thresholds were 1.5 times better for the younger than for the older group. Significant age effects were observed for SMRT thresholds and for frequency thresholds only in the basal region. SMRT thresholds were significantly correlated with frequency thresholds only in the older group. The poorer frequency and spectro-temporal pattern perception may contribute to age-related deficits in speech perception, even when audiometric thresholds are nearly normal.
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Affiliation(s)
- Duo-Duo Tao
- Department of Ear, Nose, and Throat, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Bin Shi
- Department of Ear, Nose, and Throat, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - John J. Galvin
- House Institute Foundation, Los Angeles, CA, 90057, USA
- University Hospital Center of Tours, Tours, 37000, France
| | - Ji-Sheng Liu
- Department of Ear, Nose, and Throat, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Qian-Jie Fu
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095, USA
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Cochlear Implant Facilitates the Use of Talker Sex and Spatial Cues to Segregate Competing Speech in Unilaterally Deaf Listeners. Ear Hear 2023; 44:77-91. [PMID: 35733275 DOI: 10.1097/aud.0000000000001254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Talker sex and spatial cues can facilitate segregation of competing speech. However, the spectrotemporal degradation associated with cochlear implants (CIs) can limit the benefit of talker sex and spatial cues. Acoustic hearing in the nonimplanted ear can improve access to talker sex cues in CI users. However, it's unclear whether the CI can improve segregation of competing speech when maskers are symmetrically placed around the target (i.e., when spatial cues are available), compared with acoustic hearing alone. The aim of this study was to investigate whether a CI can improve segregation of competing speech by individuals with unilateral hearing loss. DESIGN Speech recognition thresholds (SRTs) for competing speech were measured in 16 normal-hearing (NH) adults and 16 unilaterally deaf CI users. All participants were native speakers of Mandarin Chinese. CI users were divided into two groups according to thresholds in the nonimplanted ear: (1) single-sided deaf (SSD); pure-tone thresholds <25 dB HL at all audiometric frequencies, and (2) Asymmetric hearing loss (AHL; one or more thresholds > 25 dB HL). SRTs were measured for target sentences produced by a male talker in the presence of two masker talkers (different male or female talkers). The target sentence was always presented via loudspeaker directly in front of the listener (0°), and the maskers were either colocated with the target (0°) or spatially separated from the target at ±90°. Three segregation cue conditions were tested to measure masking release (MR) relative to the baseline condition: (1) Talker sex, (2) Spatial, and (3) Talker sex + Spatial. For CI users, SRTs were measured with the CI on or off. RESULTS Binaural MR was significantly better for the NH group than for the AHL or SSD groups ( P < 0.001 in all cases). For the NH group, mean MR was largest with the Talker sex + spatial cues (18.8 dB) and smallest for the Talker sex cues (10.7 dB). In contrast, mean MR for the SSD group was largest with the Talker sex + spatial cues (14.7 dB), and smallest with the Spatial cues (4.8 dB). For the AHL group, mean MR was largest with the Talker sex + spatial cues (7.8 dB) and smallest with the Talker sex (4.8 dB) and the Spatial cues (4.8 dB). MR was significantly better with the CI on than off for both the AHL ( P = 0.014) and SSD groups ( P < 0.001). Across all unilaterally deaf CI users, monaural (acoustic ear alone) and binaural MR were significantly correlated with unaided pure-tone average thresholds in the nonimplanted ear for the Talker sex and Talker sex + spatial conditions ( P < 0.001 in both cases) but not for the Spatial condition. CONCLUSION Although the CI benefitted unilaterally deaf listeners' segregation of competing speech, MR was much poorer than that observed in NH listeners. Different from previous findings with steady noise maskers, the CI benefit for segregation of competing speech from a different talker sex was greater in the SSD group than in the AHL group.
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Kopsch AC, Rahne T, Plontke SK, Wagner L. Influence of the spread of electric field on neural excitation in cochlear implant users: Transimpedance and spread of excitation measurements. Hear Res 2022; 424:108591. [PMID: 35914395 DOI: 10.1016/j.heares.2022.108591] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 07/11/2022] [Accepted: 07/21/2022] [Indexed: 11/04/2022]
Abstract
Channel interactions caused by spread of the intracochlear electric field and, thus, the spread of neural excitation constrain frequency selectivity and speech recognition in cochlear implant (CI) users. Studying the influence of the spread of electric field (SEF) on the spread of excitation (SOE) can help us better understand the electrical-neural interface. The primary aim of this study was to examine the influence of the SEF on the SOE. In 38 Nucleus (Cochlear Ltd. Sydney, Australia) CI recipients, we assessed the spatial SEF by measuring the voltage drop (transimpedance) and the SOE through neural responses (electrically evoked compound action potentials [eCAPs]) along the electrode array. Transimpedance was recorded using the monopolar (MP2) mode as the stimulation and recording mode. Biphasic square-wave pulses with an amplitude of 110 CL and duration of 37 µs were used for stimulation. SOE was measured at the probe active electrodes E5, E13, and E18. The stimulation amplitudes were set individually to the thresholds of the neural response telemetry (T-NRT), which were measured by the AutoNRT protocol. The transimpedance half-widths were between 0.00 electrodes and 8.55 electrodes. The SOE half-widths reached values between 0.54 electrodes and 5.70 electrodes. Considering individual transimpedance and SOE half-widths, the SEF and SOE showed a significant positive correlation only at electrode E13. Furthermore, this study shows a significant negative correlation of the SEF and SOE in consideration of mean half-widths.
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Affiliation(s)
- Anna C Kopsch
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, University Medicine Halle, Halle, Germany.
| | - Torsten Rahne
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, University Medicine Halle, Halle, Germany.
| | - Stefan K Plontke
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, University Medicine Halle, Halle, Germany.
| | - Luise Wagner
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, University Medicine Halle, Halle, Germany.
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Effects of Hearing Loss on School-Aged Children's Ability to Benefit From F0 Differences Between Target and Masker Speech. Ear Hear 2021; 42:1084-1096. [PMID: 33538428 PMCID: PMC8222052 DOI: 10.1097/aud.0000000000000979] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The objectives of the study were to (1) evaluate the impact of hearing loss on children's ability to benefit from F0 differences between target/masker speech in the context of aided speech-in-speech recognition and (2) to determine whether compromised F0 discrimination associated with hearing loss predicts F0 benefit in individual children. We hypothesized that children wearing appropriately fitted amplification would benefit from F0 differences, but they would not show the same magnitude of benefit as children with normal hearing. Reduced audibility and poor suprathreshold encoding that degrades frequency discrimination were expected to impair children's ability to segregate talkers based on F0. DESIGN Listeners were 9 to 17 year olds with bilateral, symmetrical, sensorineural hearing loss ranging in degree from mild to severe. A four-alternative, forced-choice procedure was used to estimate thresholds for disyllabic word recognition in a 60-dB-SPL two-talker masker. The same male talker produced target and masker speech. Target words had either the same mean F0 as the masker or were digitally shifted higher than the masker by three, six, or nine semitones. The F0 benefit was defined as the difference in thresholds between the shifted-F0 conditions and the unshifted-F0 condition. Thresholds for discriminating F0 were also measured, using a three-alternative, three-interval forced choice procedure, to determine whether compromised sensitivity to F0 differences due to hearing loss would predict children's ability to benefit from F0. Testing was performed in the sound field, and all children wore their personal hearing aids at user settings. RESULTS Children with hearing loss benefited from an F0 difference of nine semitones between target words and masker speech, with older children generally benefitting more than younger children. Some children benefitted from an F0 difference of six semitones, but this was not consistent across listeners. Thresholds for discriminating F0 improved with increasing age and predicted F0 benefit in the nine-semitone condition. An exploratory analysis indicated that F0 benefit was not significantly correlated with the four-frequency pure-tone average (0.5, 1, 2, and 4 kHz), aided audibility, or consistency of daily hearing aid use, although there was a trend for an association with the low-frequency pure-tone average (0.25 and 0.5 kHz). Comparisons of the present data to our previous study of children with normal hearing demonstrated that children with hearing loss benefitted less than children with normal hearing for the F0 differences tested. CONCLUSIONS The results demonstrate that children with mild-to-severe hearing loss who wear hearing aids benefit from relatively large F0 differences between target and masker speech during aided speech-in-speech recognition. The size of the benefit increases with increasing age, consistent with previously reported age effects for children with normal hearing. However, hearing loss reduces children's ability to capitalize on F0 differences between talkers. Audibility alone does not appear to be responsible for this effect; aided audibility and degree of loss were not primary predictors of performance. The ability to benefit from F0 differences may be limited by immature central processing or aspects of peripheral encoding that are not characterized in standard clinical assessments.
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Liu Y, Xu R, Gong Q. Human Auditory-Frequency Tuning Is Sensitive to Tonal Language Experience. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2020; 63:4277-4288. [PMID: 33151817 DOI: 10.1044/2020_jslhr-20-00152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Purpose The aim of this study is to investigate whether human auditory frequency tuning can be influenced by tonal language experience. Method Perceptual tuning measured via psychophysical tuning curves and cochlear tuning derived via stimulus-frequency otoacoustic emission suppression tuning curves in 14 native speakers of a tonal language (Mandarin) were compared to those of 14 native speakers of a nontonal language (English) at 1 and 4 kHz. Results Group comparisons of both psychophysical tuning curves (p = .046) and stimulus-frequency otoacoustic emission suppression tuning curves (p = .007) in the 4-kHz region indicated sharper frequency tuning in the Mandarin-speaking group relative to the English-speaking group. The auditory tuning was better at the higher (4 kHz) than the lower (1 kHz) probe frequencies (p < .001). Conclusions The sharper auditory tuning in the 4-kHz cochlear region is associated with long-term tonal language (i.e., Mandarin) experience. Experience-dependent plasticity of tonal language may occur before the sound signal reaches central neural stages, as peripheral as the cochlea.
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Affiliation(s)
- Yin Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Runyi Xu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Qin Gong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
- School of Medicine, Shanghai University, China
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Quass GL, Baumhoff P, Gnansia D, Stahl P, Kral A. Level coding by phase duration and asymmetric pulse shape reduce channel interactions in cochlear implants. Hear Res 2020; 396:108070. [PMID: 32950954 DOI: 10.1016/j.heares.2020.108070] [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: 06/03/2020] [Revised: 08/21/2020] [Accepted: 08/31/2020] [Indexed: 10/23/2022]
Abstract
Conventional loudness coding with CIs by pulse current amplitude has a disadvantage: Increasing the stimulation current increases the spread of excitation in the auditory nerve, resulting in stronger channel interactions at high stimulation levels. These limit the number of effective information channels that a CI user can perceive. Stimulus intensity information (loudness) can alternatively be transmitted via pulse phase duration. We hypothesized that loudness coding by phase duration avoids the increase in the spread of the electric field and thus leads to less channel interactions at high stimulation levels. To avoid polarity effects, we combined this coding with pseudomonophasic stimuli. To test whether this affects the spread of excitation, 16 acutely deafened guinea pigs were implanted with CIs and neural activity from the inferior colliculus was recorded while stimulating with either biphasic, amplitude-coded pulses, or pseudomonophasic, duration- or amplitude-coded pulses. Pseudomonophasic stimuli combined with phase duration loudness coding reduced the lowest response thresholds and the spread of excitation. We investigated the channel interactions at suprathreshold levels by computing the phase-locking to a pulse train in the presence of an interacting pulse train on a different electrode on the CI. Pseudomonophasic pulses coupled with phase duration loudness coding reduced the interference by 4-5% compared to biphasic pulses, depending on the place of stimulation. This effect of pseudomonophasic stimuli was achieved with amplitude coding only in the basal cochlea, indicating a distance- or volume dependent effect. Our results show that pseudomonophasic, phase-duration-coded stimuli slightly reduce channel interactions, suggesting a potential benefit for speech understanding in humans.
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Affiliation(s)
- Gunnar Lennart Quass
- Institute for AudioNeuroTechnology (VIANNA), ENT Clinics, Hannover Medical School, 30625 Hannover, Germany; Cluster of Excellence "Hearing4All" (EXC 2177).
| | - Peter Baumhoff
- Institute for AudioNeuroTechnology (VIANNA), ENT Clinics, Hannover Medical School, 30625 Hannover, Germany
| | | | | | - Andrej Kral
- Institute for AudioNeuroTechnology (VIANNA), ENT Clinics, Hannover Medical School, 30625 Hannover, Germany; Cluster of Excellence "Hearing4All" (EXC 2177)
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11
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Popham S, Boebinger D, Ellis DPW, Kawahara H, McDermott JH. Inharmonic speech reveals the role of harmonicity in the cocktail party problem. Nat Commun 2018; 9:2122. [PMID: 29844313 PMCID: PMC5974276 DOI: 10.1038/s41467-018-04551-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 05/08/2018] [Indexed: 11/22/2022] Open
Abstract
The "cocktail party problem" requires us to discern individual sound sources from mixtures of sources. The brain must use knowledge of natural sound regularities for this purpose. One much-discussed regularity is the tendency for frequencies to be harmonically related (integer multiples of a fundamental frequency). To test the role of harmonicity in real-world sound segregation, we developed speech analysis/synthesis tools to perturb the carrier frequencies of speech, disrupting harmonic frequency relations while maintaining the spectrotemporal envelope that determines phonemic content. We find that violations of harmonicity cause individual frequencies of speech to segregate from each other, impair the intelligibility of concurrent utterances despite leaving intelligibility of single utterances intact, and cause listeners to lose track of target talkers. However, additional segregation deficits result from replacing harmonic frequencies with noise (simulating whispering), suggesting additional grouping cues enabled by voiced speech excitation. Our results demonstrate acoustic grouping cues in real-world sound segregation.
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Affiliation(s)
- Sara Popham
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, 02139, USA
- Helen Wills Neuroscience Institute, UC Berkeley, Berkeley, CA, 94720, USA
| | - Dana Boebinger
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, 02139, USA
- Program in Speech and Hearing Sciences, Harvard University, Cambridge, MA, 02138, USA
| | | | | | - Josh H McDermott
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, 02139, USA.
- Program in Speech and Hearing Sciences, Harvard University, Cambridge, MA, 02138, USA.
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Abstract
OBJECTIVES Adults can use slow temporal envelope cues, or amplitude modulation (AM), to identify speech sounds in quiet. Faster AM cues and the temporal fine structure, or frequency modulation (FM), play a more important role in noise. This study assessed whether fast and slow temporal modulation cues play a similar role in infants' speech perception by comparing the ability of normal-hearing 3-month-olds and adults to use slow temporal envelope cues in discriminating consonants contrasts. DESIGN English consonant-vowel syllables differing in voicing or place of articulation were processed by 2 tone-excited vocoders to replace the original FM cues with pure tones in 32 frequency bands. AM cues were extracted in each frequency band with 2 different cutoff frequencies, 256 or 8 Hz. Discrimination was assessed for infants and adults using an observer-based testing method, in quiet or in a speech-shaped noise. RESULTS For infants, the effect of eliminating fast AM cues was the same in quiet and in noise: a high proportion of infants discriminated when both fast and slow AM cues were available, but less than half of the infants also discriminated when only slow AM cues were preserved. For adults, the effect of eliminating fast AM cues was greater in noise than in quiet: All adults discriminated in quiet whether or not fast AM cues were available, but in noise eliminating fast AM cues reduced the percentage of adults reaching criterion from 71 to 21%. CONCLUSIONS In quiet, infants seem to depend on fast AM cues more than adults do. In noise, adults seem to depend on FM cues to a greater extent than infants do. However, infants and adults are similarly affected by a loss of fast AM cues in noise. Experience with the native language seems to change the relative importance of different acoustic cues for speech perception.
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Aushana Y, Souffi S, Edeline JM, Lorenzi C, Huetz C. Robust Neuronal Discrimination in Primary Auditory Cortex Despite Degradations of Spectro-temporal Acoustic Details: Comparison Between Guinea Pigs with Normal Hearing and Mild Age-Related Hearing Loss. J Assoc Res Otolaryngol 2018; 19:163-180. [PMID: 29302822 PMCID: PMC5878150 DOI: 10.1007/s10162-017-0649-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 12/11/2017] [Indexed: 01/04/2023] Open
Abstract
This study investigated to which extent the primary auditory cortex of young normal-hearing and mild hearing-impaired aged animals is able to maintain invariant representation of critical temporal-modulation features when sounds are submitted to degradations of fine spectro-temporal acoustic details. This was achieved by recording ensemble of cortical responses to conspecific vocalizations in guinea pigs with either normal hearing or mild age-related sensorineural hearing loss. The vocalizations were degraded using a tone vocoder. The neuronal responses and their discrimination capacities (estimated by mutual information) were analyzed at single recording and population levels. For normal-hearing animals, the neuronal responses decreased as a function of the number of the vocoder frequency bands, so did their discriminative capacities at the single recording level. However, small neuronal populations were found to be robust to the degradations induced by the vocoder. Similar robustness was obtained when broadband noise was added to exacerbate further the spectro-temporal distortions produced by the vocoder. A comparable pattern of robustness to degradations in fine spectro-temporal details was found for hearing-impaired animals. However, the latter showed an overall decrease in neuronal discrimination capacities between vocalizations in noisy conditions. Consistent with previous studies, these results demonstrate that the primary auditory cortex maintains robust neural representation of temporal envelope features for communication sounds under a large range of spectro-temporal degradations.
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Affiliation(s)
- Yonane Aushana
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Orsay, France
- Université Paris-Sud, 91405 Orsay cedex, France
- Université Paris-Saclay, 91405 Orsay cedex, France
| | - Samira Souffi
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Orsay, France
- Université Paris-Sud, 91405 Orsay cedex, France
- Université Paris-Saclay, 91405 Orsay cedex, France
| | - Jean-Marc Edeline
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Orsay, France
- Université Paris-Sud, 91405 Orsay cedex, France
- Université Paris-Saclay, 91405 Orsay cedex, France
| | - Christian Lorenzi
- Laboratoire des Systèmes Perceptifs, UMR CNRS 8248, Département d’Etudes Cognitives, Ecole Normale Supérieure (ENS), Paris Sciences & Lettres Research University, 75005 Paris, France
| | - Chloé Huetz
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Orsay, France
- Université Paris-Sud, 91405 Orsay cedex, France
- Université Paris-Saclay, 91405 Orsay cedex, France
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14
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Abstract
OBJECTIVES The purpose of the present study was to quantify age-related differences in executive control as it relates to dual-task performance, which is thought to represent listening effort, during degraded speech recognition. DESIGN Twenty-five younger adults (YA; 18-24 years) and 21 older adults (OA; 56-82 years) completed a dual-task paradigm that consisted of a primary speech recognition task and a secondary visual monitoring task. Sentence material in the primary task was either unprocessed or spectrally degraded into 8, 6, or 4 spectral channels using noise-band vocoding. Performance on the visual monitoring task was assessed by the accuracy and reaction time of participants' responses. Performance on the primary and secondary task was quantified in isolation (i.e., single task) and during the dual-task paradigm. Participants also completed a standardized psychometric measure of executive control, including attention and inhibition. Statistical analyses were implemented to evaluate changes in listeners' performance on the primary and secondary tasks (1) per condition (unprocessed vs. vocoded conditions); (2) per task (single task vs. dual task); and (3) per group (YA vs. OA). RESULTS Speech recognition declined with increasing spectral degradation for both YA and OA when they performed the task in isolation or concurrently with the visual monitoring task. OA were slower and less accurate than YA on the visual monitoring task when performed in isolation, which paralleled age-related differences in standardized scores of executive control. When compared with single-task performance, OA experienced greater declines in secondary-task accuracy, but not reaction time, than YA. Furthermore, results revealed that age-related differences in executive control significantly contributed to age-related differences on the visual monitoring task during the dual-task paradigm. CONCLUSIONS OA experienced significantly greater declines in secondary-task accuracy during degraded speech recognition than YA. These findings are interpreted as suggesting that OA expended greater listening effort than YA, which may be partially attributed to age-related differences in executive control.
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van de Velde DJ, Schiller NO, van Heuven VJ, Levelt CC, van Ginkel J, Beers M, Briaire JJ, Frijns JHM. The perception of emotion and focus prosody with varying acoustic cues in cochlear implant simulations with varying filter slopes. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:3349. [PMID: 28599540 PMCID: PMC5436976 DOI: 10.1121/1.4982198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/15/2017] [Accepted: 04/11/2017] [Indexed: 06/07/2023]
Abstract
This study aimed to find the optimal filter slope for cochlear implant simulations (vocoding) by testing the effect of a wide range of slopes on the discrimination of emotional and linguistic (focus) prosody, with varying availability of F0 and duration cues. Forty normally hearing participants judged if (non-)vocoded sentences were pronounced with happy or sad emotion, or with adjectival or nominal focus. Sentences were recorded as natural stimuli and manipulated to contain only emotion- or focus-relevant segmental duration or F0 information or both, and then noise-vocoded with 5, 20, 80, 120, and 160 dB/octave filter slopes. Performance increased with steeper slopes, but only up to 120 dB/octave, with bigger effects for emotion than for focus perception. For emotion, results with both cues most closely resembled results with F0, while for focus results with both cues most closely resembled those with duration, showing emotion perception relies primarily on F0, and focus perception on duration. This suggests that filter slopes affect focus perception less than emotion perception because for emotion, F0 is both more informative and more affected. The performance increase until extreme filter slope values suggests that much performance improvement in prosody perception is still to be gained for CI users.
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Affiliation(s)
- Daan J van de Velde
- Leiden University Centre for Linguistics, Leiden University, Van Wijkplaats 3, 2311 BX, Leiden, the Netherlands
| | - Niels O Schiller
- Leiden University Centre for Linguistics, Leiden University, Van Wijkplaats 3, 2311 BX, Leiden, the Netherlands
| | - Vincent J van Heuven
- Department of Applied Linguistics, Pannon Egyetem, 10 Egyetem Utca, 8200 Veszprém, Hungary
| | - Claartje C Levelt
- Leiden University Centre for Linguistics, Leiden University, Van Wijkplaats 3, 2311 BX, Leiden, the Netherlands
| | - Joost van Ginkel
- Leiden University Centre for Child and Family Studies, Wassenaarseweg 52, 2333 AK, Leiden, the Netherlands
| | - Mieke Beers
- Leiden University Medical Center, Ears, Nose, and Throat Department, Postbus 9600, 2300 RC, Leiden, the Netherlands
| | - Jeroen J Briaire
- Leiden University Medical Center, Ears, Nose, and Throat Department, Postbus 9600, 2300 RC, Leiden, the Netherlands
| | - Johan H M Frijns
- Leiden University Medical Center, Ears, Nose, and Throat Department, Postbus 9600, 2300 RC, Leiden, the Netherlands
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16
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Başkent D, Clarke J, Pals C, Benard MR, Bhargava P, Saija J, Sarampalis A, Wagner A, Gaudrain E. Cognitive Compensation of Speech Perception With Hearing Impairment, Cochlear Implants, and Aging. Trends Hear 2016. [PMCID: PMC5056620 DOI: 10.1177/2331216516670279] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
External degradations in incoming speech reduce understanding, and hearing impairment further compounds the problem. While cognitive mechanisms alleviate some of the difficulties, their effectiveness may change with age. In our research, reviewed here, we investigated cognitive compensation with hearing impairment, cochlear implants, and aging, via (a) phonemic restoration as a measure of top-down filling of missing speech, (b) listening effort and response times as a measure of increased cognitive processing, and (c) visual world paradigm and eye gazing as a measure of the use of context and its time course. Our results indicate that between speech degradations and their cognitive compensation, there is a fine balance that seems to vary greatly across individuals. Hearing impairment or inadequate hearing device settings may limit compensation benefits. Cochlear implants seem to allow the effective use of sentential context, but likely at the cost of delayed processing. Linguistic and lexical knowledge, which play an important role in compensation, may be successfully employed in advanced age, as some compensatory mechanisms seem to be preserved. These findings indicate that cognitive compensation in hearing impairment can be highly complicated—not always absent, but also not easily predicted by speech intelligibility tests only.
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Affiliation(s)
- Deniz Başkent
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
| | - Jeanne Clarke
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
| | - Carina Pals
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
| | - Michel R. Benard
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Pento Speech and Hearing Center Zwolle, Zwolle, Netherlands
| | - Pranesh Bhargava
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
| | - Jefta Saija
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
| | - Anastasios Sarampalis
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
- Department of Psychology, University of Groningen, Netherlands
| | - Anita Wagner
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
| | - Etienne Gaudrain
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Netherlands
- Graduate School of Medical Sciences, University of Groningen, Netherlands
- Research School of Behavioural and Cognitive Neurosciences, University of Groningen, Netherlands
- Auditory Cognition and Psychoacoustics, CNRS, Lyon Neuroscience Research Center, Lyon, France
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17
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Bidelman GM, Nelms C, Bhagat SP. Musical experience sharpens human cochlear tuning. Hear Res 2016; 335:40-46. [DOI: 10.1016/j.heares.2016.02.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/06/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
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18
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Won JH, Moon IJ, Jin S, Park H, Woo J, Cho YS, Chung WH, Hong SH. Spectrotemporal Modulation Detection and Speech Perception by Cochlear Implant Users. PLoS One 2015; 10:e0140920. [PMID: 26485715 PMCID: PMC4617902 DOI: 10.1371/journal.pone.0140920] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 10/01/2015] [Indexed: 11/18/2022] Open
Abstract
Spectrotemporal modulation (STM) detection performance was examined for cochlear implant (CI) users. The test involved discriminating between an unmodulated steady noise and a modulated stimulus. The modulated stimulus presents frequency modulation patterns that change in frequency over time. In order to examine STM detection performance for different modulation conditions, two different temporal modulation rates (5 and 10 Hz) and three different spectral modulation densities (0.5, 1.0, and 2.0 cycles/octave) were employed, producing a total 6 different STM stimulus conditions. In order to explore how electric hearing constrains STM sensitivity for CI users differently from acoustic hearing, normal-hearing (NH) and hearing-impaired (HI) listeners were also tested on the same tasks. STM detection performance was best in NH subjects, followed by HI subjects. On average, CI subjects showed poorest performance, but some CI subjects showed high levels of STM detection performance that was comparable to acoustic hearing. Significant correlations were found between STM detection performance and speech identification performance in quiet and in noise. In order to understand the relative contribution of spectral and temporal modulation cues to speech perception abilities for CI users, spectral and temporal modulation detection was performed separately and related to STM detection and speech perception performance. The results suggest that that slow spectral modulation rather than slow temporal modulation may be important for determining speech perception capabilities for CI users. Lastly, test–retest reliability for STM detection was good with no learning. The present study demonstrates that STM detection may be a useful tool to evaluate the ability of CI sound processing strategies to deliver clinically pertinent acoustic modulation information.
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Affiliation(s)
- Jong Ho Won
- Division of Ophthalmic and Ear, Nose and Throat Devices, Office of Device Evaluation, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland, United States of America
| | - Il Joon Moon
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, Republic of Korea
- * E-mail:
| | - Sunhwa Jin
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, Republic of Korea
| | - Heesung Park
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, Republic of Korea
| | - Jihwan Woo
- School of Electrical Engineering, Biomedical Engineering, University of Ulsan, Ulsan 680-749, Republic of Korea
| | - Yang-Sun Cho
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, Republic of Korea
| | - Won-Ho Chung
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, Republic of Korea
| | - Sung Hwa Hong
- Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 135-710, Republic of Korea
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Kates JM, Arehart KH. Comparing the information conveyed by envelope modulation for speech intelligibility, speech quality, and music quality. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:2470-82. [PMID: 26520329 PMCID: PMC4627935 DOI: 10.1121/1.4931899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This paper uses mutual information to quantify the relationship between envelope modulation fidelity and perceptual responses. Data from several previous experiments that measured speech intelligibility, speech quality, and music quality are evaluated for normal-hearing and hearing-impaired listeners. A model of the auditory periphery is used to generate envelope signals, and envelope modulation fidelity is calculated using the normalized cross-covariance of the degraded signal envelope with that of a reference signal. Two procedures are used to describe the envelope modulation: (1) modulation within each auditory frequency band and (2) spectro-temporal processing that analyzes the modulation of spectral ripple components fit to successive short-time spectra. The results indicate that low modulation rates provide the highest information for intelligibility, while high modulation rates provide the highest information for speech and music quality. The low-to-mid auditory frequencies are most important for intelligibility, while mid frequencies are most important for speech quality and high frequencies are most important for music quality. Differences between the spectral ripple components used for the spectro-temporal analysis were not significant in five of the six experimental conditions evaluated. The results indicate that different modulation-rate and auditory-frequency weights may be appropriate for indices designed to predict different types of perceptual relationships.
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Affiliation(s)
- James M Kates
- Department of Speech Language and Hearing Sciences, University of Colorado, Boulder, Colorado 80309, USA
| | - Kathryn H Arehart
- Department of Speech Language and Hearing Sciences, University of Colorado, Boulder, Colorado 80309, USA
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20
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George SS, Shivdasani MN, Wise AK, Shepherd RK, Fallon JB. Electrophysiological channel interactions using focused multipolar stimulation for cochlear implants. J Neural Eng 2015; 12:066005. [DOI: 10.1088/1741-2560/12/6/066005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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21
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Léger AC, Reed CM, Desloge JG, Swaminathan J, Braida LD. Consonant identification in noise using Hilbert-transform temporal fine-structure speech and recovered-envelope speech for listeners with normal and impaired hearing. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:389-403. [PMID: 26233038 PMCID: PMC4514718 DOI: 10.1121/1.4922949] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 04/07/2015] [Accepted: 06/11/2015] [Indexed: 05/31/2023]
Abstract
Consonant-identification ability was examined in normal-hearing (NH) and hearing-impaired (HI) listeners in the presence of steady-state and 10-Hz square-wave interrupted speech-shaped noise. The Hilbert transform was used to process speech stimuli (16 consonants in a-C-a syllables) to present envelope cues, temporal fine-structure (TFS) cues, or envelope cues recovered from TFS speech. The performance of the HI listeners was inferior to that of the NH listeners both in terms of lower levels of performance in the baseline condition and in the need for higher signal-to-noise ratio to yield a given level of performance. For NH listeners, scores were higher in interrupted noise than in steady-state noise for all speech types (indicating substantial masking release). For HI listeners, masking release was typically observed for TFS and recovered-envelope speech but not for unprocessed and envelope speech. For both groups of listeners, TFS and recovered-envelope speech yielded similar levels of performance and consonant confusion patterns. The masking release observed for TFS and recovered-envelope speech may be related to level effects associated with the manner in which the TFS processing interacts with the interrupted noise signal, rather than to the contributions of TFS cues per se.
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Affiliation(s)
- Agnès C Léger
- School of Psychological Sciences, University of Manchester, Manchester, M13 9PL, United Kingdom
| | - Charlotte M Reed
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Joseph G Desloge
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jayaganesh Swaminathan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Louis D Braida
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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22
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Cabrera L, Lorenzi C, Bertoncini J. Infants Discriminate Voicing and Place of Articulation With Reduced Spectral and Temporal Modulation Cues. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2015; 58:1033-1042. [PMID: 25682333 DOI: 10.1044/2015_jslhr-h-14-0121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 02/02/2015] [Indexed: 06/04/2023]
Abstract
PURPOSE This study assessed the role of spectro-temporal modulation cues in the discrimination of 2 phonetic contrasts (voicing and place) for young infants. METHOD A visual-habituation procedure was used to assess the ability of French-learning 6-month-old infants with normal hearing to discriminate voiced versus unvoiced (/aba/-/apa/) and labial versus dental (/aba/-/ada/) stop consonants. The stimuli were processed by tone-excited vocoders to degrade frequency-modulation cues while preserving: (a) amplitude-modulation (AM) cues within 32 analysis frequency bands, (b) slow AM cues only (<16 Hz) within 32 bands, and (c) AM cues within 8 bands. RESULTS Infants exhibited discrimination responses for both phonetic contrasts in each processing condition. However, when fast AM cues were degraded, infants required a longer exposure to vocoded stimuli to reach the habituation criterion. CONCLUSIONS Altogether, these results indicate that the processing of modulation cues conveying phonetic information on voicing and place is "functional" at 6 months. The data also suggest that the perceptual weight of fast AM speech cues may change during development.
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23
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Léger AC, Desloge JG, Braida LD, Swaminathan J. The role of recovered envelope cues in the identification of temporal-fine-structure speech for hearing-impaired listeners. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:505-508. [PMID: 25618081 PMCID: PMC4304958 DOI: 10.1121/1.4904540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 11/14/2014] [Accepted: 11/26/2014] [Indexed: 06/01/2023]
Abstract
Narrowband speech can be separated into fast temporal cues [temporal fine structure (TFS)], and slow amplitude modulations (envelope). Speech processed to contain only TFS leads to envelope recovery through cochlear filtering, which has been suggested to account for TFS-speech intelligibility for normal-hearing listeners. Hearing-impaired listeners have deficits with TFS-speech identification, but the contribution of recovered-envelope cues to these deficits is unknown. This was assessed for hearing-impaired listeners by measuring identification of disyllables processed to contain TFS or recovered-envelope cues. Hearing-impaired listeners performed worse than normal-hearing listeners, but TFS-speech intelligibility was accounted for by recovered-envelope cues for both groups.
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Affiliation(s)
- Agnès C Léger
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-757, Cambridge, Massachusetts 02139
| | - Joseph G Desloge
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-757, Cambridge, Massachusetts 02139
| | - Louis D Braida
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-757, Cambridge, Massachusetts 02139
| | - Jayaganesh Swaminathan
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-757, Cambridge, Massachusetts 02139
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Warner-Czyz AD, Houston DM, Hynan LS. Vowel discrimination by hearing infants as a function of number of spectral channels. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2014; 135:3017-24. [PMID: 24815281 PMCID: PMC4109213 DOI: 10.1121/1.4870700] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 03/26/2014] [Accepted: 03/27/2014] [Indexed: 05/15/2023]
Abstract
Reduced spectral resolution negatively impacts speech perception, particularly perception of vowels and consonant place. This study assessed impact of number of spectral channels on vowel discrimination by 6-month-old infants with normal hearing by comparing three listening conditions: Unprocessed speech, 32 channels, and 16 channels. Auditory stimuli (/ti/ and /ta/) were spectrally reduced using a noiseband vocoder and presented to infants with normal hearing via visual habituation. Results supported a significant effect of number of channels on vowel discrimination by 6-month-old infants. No differences emerged between unprocessed and 32-channel conditions in which infants looked longer during novel stimulus trials (i.e., discrimination). The 16-channel condition yielded a significantly different pattern: Infants demonstrated no significant difference in looking time to familiar vs novel stimulus trials, suggesting infants cannot discriminate /ti/ and /ta/ with only 16 channels. Results support effects of spectral resolution on vowel discrimination. Relative to published reports, young infants need more spectral detail than older children and adults to perceive spectrally degraded speech. Results have implications for development of perception by infants with hearing loss who receive auditory prostheses.
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Affiliation(s)
- Andrea D Warner-Czyz
- Department of Communication Sciences and Disorders, The University of Texas at Dallas, Callier Advanced Hearing Research Center, 1966 Inwood Road, Dallas, Texas 75235
| | - Derek M Houston
- Department of Otolaryngology, Head and Neck Surgery, Indiana University School of Medicine, 699 Riley Hospital Drive/RR044, Indianapolis, Indiana 46202
| | - Linda S Hynan
- Departments of Clinical Sciences and Psychiatry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390
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Başkent D, van Engelshoven S, Galvin JJ. Susceptibility to interference by music and speech maskers in middle-aged adults. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2014; 135:EL147-EL153. [PMID: 24606308 PMCID: PMC4043475 DOI: 10.1121/1.4865261] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/05/2013] [Accepted: 12/17/2013] [Indexed: 06/03/2023]
Abstract
Older listeners commonly complain about difficulty in understanding speech in noise. Previous studies have shown an age effect for both speech and steady noise maskers, and it is largest for speech maskers. In the present study, speech reception thresholds (SRTs) measured with competing speech, music, and steady noise maskers significantly differed between young (19 to 26 years) and middle-aged (51 to 63 years) adults. SRT differences ranged from 2.1 dB for competing speech, 0.4-1.6 dB for music maskers, and 0.8 dB for steady noise. The data suggest that aging effects are already evident in middle-aged adults without significant hearing impairment.
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Affiliation(s)
- Deniz Başkent
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Suzanne van Engelshoven
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - John J Galvin
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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26
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Anderson MC, Arehart KH, Kates JM. The effects of noise vocoding on speech quality perception. Hear Res 2014; 309:75-83. [DOI: 10.1016/j.heares.2013.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 11/22/2013] [Accepted: 11/25/2013] [Indexed: 10/25/2022]
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Gnansia D, Lazard DS, Léger AC, Fugain C, Lancelin D, Meyer B, Lorenzi C. Role of slow temporal modulations in speech identification for cochlear implant users. Int J Audiol 2013; 53:48-54. [PMID: 24195655 DOI: 10.3109/14992027.2013.844367] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This study aimed to assess whether the capacity of cochlear implant (CI) users to identify speech is determined by their capacity to perceive slow (< 20 Hz) temporal modulations. DESIGN This was achieved by studying the correlation between (1) phoneme identification in quiet and in a steady-state or fluctuating (8 Hz) noises, and (2) amplitude-modulation detection thresholds (MDTs) at 8 Hz (i.e. slow temporal modulations). STUDY SAMPLE Twenty-one CI users, unilaterally implanted with the same device, were tested in free field with their everyday clinical processor. RESULTS Extensive variability across subjects was observed for both phoneme identification and MDTs. Vowel and consonant identification scores in quiet were significantly correlated with MDTs at 8 Hz (r = - 0.47 for consonants, r = - 0.44 for vowels; p < 0.05). When the masker was a steady-state noise, only consonant identification scores tended to correlate with MDTs at 8 Hz (r = - 0.4; p = 0.07). When the masker was a fluctuating noise, consonant and vowel identification scores were not significantly correlated with MDTs at 8 Hz. CONCLUSIONS Sensitivity to slow amplitude modulations is correlated with vowel and consonant perception in CI users. However, reduced sensitivity to slow modulations does not entirely explain the limited capacity of CI recipients to understand speech in noise.
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Başkent D, van Rij J, Ng ZY, Free R, Hendriks P. Perception of spectrally degraded reflexives and pronouns by children. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2013; 134:3844-3852. [PMID: 24180793 DOI: 10.1121/1.4824341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Speech perception skills in cochlear-implant users are often measured with simple speech materials. In children, it is crucial to fully characterize linguistic development, and this requires linguistically more meaningful materials. The authors propose using the comprehension of reflexives and pronouns, as these specific skills are acquired at different ages. According to the literature, normal-hearing children show adult-like comprehension of reflexives at age 5, while their comprehension of pronouns only reaches adult-like levels around age 10. To provide normative data, a group of younger children (5 to 8 yrs old), older children (10 and 11 yrs old), and adults were tested under conditions without or with spectral degradation, which simulated cochlear-implant speech transmission with four and eight channels. The results without degradation confirmed the different ages of acquisition of reflexives and pronouns. Adding spectral degradation reduced overall performance; however, it did not change the general pattern observed with non-degraded speech. This finding confirms that these linguistic milestones can also be measured with cochlear-implanted children, despite the reduced quality of sound transmission. Thus, the results of the study have implications for clinical practice, as they could contribute to setting realistic expectations and therapeutic goals for children who receive a cochlear implant.
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Affiliation(s)
- Deniz Başkent
- University of Groningen, University Medical Center Groningen, Department of Otorhinolaryngology/Head and Neck Surgery, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
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Pals C, Sarampalis A, Baskent D. Listening effort with cochlear implant simulations. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2013; 56:1075-1084. [PMID: 23275424 DOI: 10.1044/1092-4388(2012/12-0074)] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
PURPOSE Fitting a cochlear implant (CI) for optimal speech perception does not necessarily optimize listening effort. This study aimed to show that listening effort may change between CI processing conditions for which speech intelligibility remains constant. METHOD Nineteen normal-hearing participants listened to CI simulations with varying numbers of spectral channels. A dual-task paradigm combining an intelligibility task with either a linguistic or nonlinguistic visual response-time (RT) task measured intelligibility and listening effort. The simultaneously performed tasks compete for limited cognitive resources; changes in effort associated with the intelligibility task are reflected in changes in RT on the visual task. A separate self-report scale provided a subjective measure of listening effort. RESULTS All measures showed significant improvements with increasing spectral resolution up to 6 channels. However, only the RT measure of listening effort continued improving up to 8 channels. The effects were stronger for RTs recorded during listening than for RTs recorded between listening. CONCLUSION The results suggest that listening effort decreases with increased spectral resolution. Moreover, these improvements are best reflected in objective measures of listening effort, such as RTs on a secondary task, rather than intelligibility scores or subjective effort measures.
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Affiliation(s)
- Carina Pals
- University Medical Center Groningen, the Netherlands.
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Shamma S, Lorenzi C. On the balance of envelope and temporal fine structure in the encoding of speech in the early auditory system. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2013; 133:2818-33. [PMID: 23654388 PMCID: PMC3663870 DOI: 10.1121/1.4795783] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
There is much debate on how the spectrotemporal modulations of speech (or its spectrogram) are encoded in the responses of the auditory nerve, and whether speech intelligibility is best conveyed via the "envelope" (E) or "temporal fine-structure" (TFS) of the neural responses. Wide use of vocoders to resolve this question has commonly assumed that manipulating the amplitude-modulation and frequency-modulation components of the vocoded signal alters the relative importance of E or TFS encoding on the nerve, thus facilitating assessment of their relative importance to intelligibility. Here we argue that this assumption is incorrect, and that the vocoder approach is ineffective in differentially altering the neural E and TFS. In fact, we demonstrate using a simplified model of early auditory processing that both neural E and TFS encode the speech spectrogram with constant and comparable relative effectiveness regardless of the vocoder manipulations. However, we also show that neural TFS cues are less vulnerable than their E counterparts under severe noisy conditions, and hence should play a more prominent role in cochlear stimulation strategies.
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Affiliation(s)
- Shihab Shamma
- Electrical and Computer Engineering Department and Institute for Systems Research, University of Maryland, College Park, Maryland 20742, USA.
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Lorenzi C, Wallaert N, Gnansia D, Leger AC, Ives DT, Chays A, Garnier S, Cazals Y. Temporal-envelope reconstruction for hearing-impaired listeners. J Assoc Res Otolaryngol 2012; 13:853-65. [PMID: 23007719 PMCID: PMC3505588 DOI: 10.1007/s10162-012-0350-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Accepted: 09/09/2012] [Indexed: 10/27/2022] Open
Abstract
Recent studies suggest that normal-hearing listeners maintain robust speech intelligibility despite severe degradations of amplitude-modulation (AM) cues, by using temporal-envelope information recovered from broadband frequency-modulation (FM) speech cues at the output of cochlear filters. This study aimed to assess whether cochlear damage affects this capacity to reconstruct temporal-envelope information from FM. This was achieved by measuring the ability of 40 normal-hearing listeners and 41 listeners with mild-to-moderate hearing loss to identify syllables processed to degrade AM cues while leaving FM cues intact within three broad frequency bands spanning the range 65-3,645 Hz. Stimuli were presented at 65 dB SPL for both normal-hearing listeners and hearing-impaired listeners. They were presented as such or amplified using a modified half-gain rule for hearing-impaired listeners. Hearing-impaired listeners showed significantly poorer identification scores than normal-hearing listeners at both presentation levels. However, the deficit shown by hearing-impaired listeners for amplified stimuli was relatively modest. Overall, hearing-impaired data and the results of a simulation study were consistent with a poorer-than-normal ability to reconstruct temporal-envelope information resulting from a broadening of cochlear filters by a factor ranging from 2 to 4. These results suggest that mild-to-moderate cochlear hearing loss has only a modest detrimental effect on peripheral, temporal-envelope reconstruction mechanisms.
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Affiliation(s)
- Christian Lorenzi
- Equipe Audition (CNRS, Universite Paris Descartes, Ecole normale superieure), Institut d'Etude de la Cognition, Ecole normale superieure, Paris Sciences et Lettres, 29 rue d'Ulm, 75005 Paris, France.
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Dubno JR, Ahlstrom JB, Wang X, Horwitz AR. Level-dependent changes in perception of speech envelope cues. J Assoc Res Otolaryngol 2012; 13:835-52. [PMID: 22872414 DOI: 10.1007/s10162-012-0343-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 07/16/2012] [Indexed: 11/28/2022] Open
Abstract
Level-dependent changes in temporal envelope fluctuations in speech and related changes in speech recognition may reveal effects of basilar-membrane nonlinearities. As a result of compression in the basilar-membrane response, the "effective" magnitude of envelope fluctuations may be reduced as speech level increases from lower level (more linear) to mid-level (more compressive) regions. With further increases to a more linear region, speech envelope fluctuations may become more pronounced. To assess these effects, recognition of consonants and key words in sentences was measured as a function of speech level for younger adults with normal hearing. Consonant-vowel syllables and sentences were spectrally degraded using "noise vocoder" processing to maximize perceptual effects of changes to the speech envelope. Broadband noise at a fixed signal-to-noise ratio maintained constant audibility as speech level increased. Results revealed significant increases in scores and envelope-dependent feature transmission from 45 to 60 dB SPL and decreasing scores and feature transmission from 60 to 85 dB SPL. This quadratic pattern, with speech recognition maximized at mid levels and poorer at lower and higher levels, is consistent with a role of cochlear nonlinearities in perception of speech envelope cues.
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Affiliation(s)
- Judy R Dubno
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, 135 Rutledge Avenue, MSC 550, Charleston, SC 29425-5500, USA.
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Stone MA, Anton K, Moore BCJ. Use of high-rate envelope speech cues and their perceptually relevant dynamic range for the hearing impaired. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 132:1141-1151. [PMID: 22894233 DOI: 10.1121/1.4733543] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The ability of hearing-impaired (HI) listeners to use high-rate envelope information in a competing-talker situation was assessed. In experiment 1, signals were tone vocoded and the cutoff frequency (f(c)) of the envelope extraction filter was either 50 Hz (E filter) or 200 Hz (P filter). The channels for which the P or E filter was used were varied. Intelligibility was higher with the P filter regardless of whether it was used for low or high center frequencies. Performance was best when the P filter was used for all channels. Experiment 2 explored the dynamic range over which HI listeners made use of high-rate cues. In each channel of a vocoder, the envelope extracted using f(c) = 16 Hz was replaced by the envelope extracted using f(c) = 300 Hz, either at the peaks or valleys, with a parametrically varied "switching threshold." For a target-to-background ratio of +5 dB, changes in speech intelligibility occurred mainly when the switching threshold was between -8 and +8 dB relative to the channel root-mean-square level. This range is similar in width to, but about 3 dB higher in absolute level than, that found for normal-hearing listeners, despite the reduced dynamic range of the HI listeners.
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Affiliation(s)
- Michael A Stone
- Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, England.
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Psychophysiological analyses demonstrate the importance of neural envelope coding for speech perception in noise. J Neurosci 2012; 32:1747-56. [PMID: 22302814 DOI: 10.1523/jneurosci.4493-11.2012] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Understanding speech in noisy environments is often taken for granted; however, this task is particularly challenging for people with cochlear hearing loss, even with hearing aids or cochlear implants. A significant limitation to improving auditory prostheses is our lack of understanding of the neural basis for robust speech perception in noise. Perceptual studies suggest the slowly varying component of the acoustic waveform (envelope, ENV) is sufficient for understanding speech in quiet, but the rapidly varying temporal fine structure (TFS) is important in noise. These perceptual findings have important implications for cochlear implants, which currently only provide ENV; however, neural correlates have been difficult to evaluate due to cochlear transformations between acoustic TFS and recovered neural ENV. Here, we demonstrate the relative contributions of neural ENV and TFS by quantitatively linking neural coding, predicted from a computational auditory nerve model, with perception of vocoded speech in noise measured from normal hearing human listeners. Regression models with ENV and TFS coding as independent variables predicted speech identification and phonetic feature reception at both positive and negative signal-to-noise ratios. We found that: (1) neural ENV coding was a primary contributor to speech perception, even in noise; and (2) neural TFS contributed in noise mainly in the presence of neural ENV, but rarely as the primary cue itself. These results suggest that neural TFS has less perceptual salience than previously thought due to cochlear signal processing transformations between TFS and ENV. Because these transformations differ between normal and impaired ears, these findings have important translational implications for auditory prostheses.
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Bhargava P, Başkent D. Effects of low-pass filtering on intelligibility of periodically interrupted speech. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 131:EL87-92. [PMID: 22352622 DOI: 10.1121/1.3670000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The combined effect of low-pass filtering (cut-off frequencies between 500 and 3000 Hz) and periodic interruptions (1.5 and 10 Hz) on speech intelligibility was investigated. When combined, intelligibility was lower than each manipulation alone, even in some conditions where there was no effect from a single manipulation (such as the fast interruption rate of 10 Hz). By using young normal-hearing listeners, potential suprathreshold deficits and aging effects that may occur due to hearing impairment were eliminated. Thus, the results imply that reduced audibility of high-frequency speech components may partially explain the reduced intelligibility of interrupted speech in hearing impaired persons.
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Affiliation(s)
- Pranesh Bhargava
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
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Whitmal NA, DeRoy K. Use of an adaptive-bandwidth protocol to measure importance functions for simulated cochlear implant frequency channels. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 131:1359-1370. [PMID: 22352509 PMCID: PMC3292607 DOI: 10.1121/1.3672684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 05/29/2023]
Abstract
The Articulation Index and Speech Intelligibility Index predict intelligibility scores from measurements of speech and hearing parameters. One component in the prediction is the frequency-importance function, a weighting function that characterizes contributions of particular spectral regions of speech to speech intelligibility. The purpose of this study was to determine whether such importance functions could similarly characterize contributions of electrode channels in cochlear implant systems. Thirty-eight subjects with normal hearing listened to vowel-consonant-vowel tokens, either as recorded or as output from vocoders that simulated aspects of cochlear implant processing. Importance functions were measured using the method of Whitmal and DeRoy [J. Acoust. Soc. Am. 130, 4032-4043 (2011)], in which signal bandwidths were varied adaptively to produce specified token recognition scores in accordance with the transformed up-down rules of Levitt [J. Acoust. Soc. Am. 49, 467-477 (1971)]. Psychometric functions constructed from recognition scores were subsequently converted into importance functions. Comparisons of the resulting importance functions indicate that vocoder processing causes peak importance regions to shift downward in frequency. This shift is attributed to changes in strategy and capability for detecting voicing in speech, and is consistent with previously measured data.
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Affiliation(s)
- Nathaniel A Whitmal
- Department of Communication Disorders, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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Kates JM. Spectro-temporal envelope changes caused by temporal fine structure modification. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:3981-3990. [PMID: 21682419 DOI: 10.1121/1.3583552] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The study of speech from which the temporal fine structure (TFS) has been removed has become an important research area. Common procedures for removing TFS include noise and tone vocoders. In the noise vocoder, bands of noise are modulated by the envelope of the speech within each band, and in the tone vocoder the carrier is a sinusoid at the center of each frequency band. Five different procedures for removing TFS are evaluated in this paper: the noise vocoder, a low-noise noise approach in which the noise envelope is replaced by the speech envelope in each frequency band, phase randomization within each band, the tone vocoder, and sinusoidal modeling with random phase. The effects of TFS modification on the speech envelope are evaluated using an index based on the envelope time-frequency modulation. The results show that for all of the TFS techniques implemented in this study, there is a substantial loss in the accuracy of reproduction of the envelope time-frequency modulation. The tone vocoder gives the best accuracy, followed by the procedure that replaces the noise envelope with the speech envelope in each band.
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Affiliation(s)
- James M Kates
- GN ReSound A/S, 3215 Marine Street, Room W161, Boulder, Colorado 80309, USA.
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Swaminathan J, Heinz MG. Predicted effects of sensorineural hearing loss on across-fiber envelope coding in the auditory nerve. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:4001-13. [PMID: 21682421 PMCID: PMC3135152 DOI: 10.1121/1.3583502] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 12/23/2010] [Accepted: 03/30/2011] [Indexed: 05/19/2023]
Abstract
Cross-channel envelope correlations are hypothesized to influence speech intelligibility, particularly in adverse conditions. Acoustic analyses suggest speech envelope correlations differ for syllabic and phonemic ranges of modulation frequency. The influence of cochlear filtering was examined here by predicting cross-channel envelope correlations in different speech modulation ranges for normal and impaired auditory-nerve (AN) responses. Neural cross-correlation coefficients quantified across-fiber envelope coding in syllabic (0-5 Hz), phonemic (5-64 Hz), and periodicity (64-300 Hz) modulation ranges. Spike trains were generated from a physiologically based AN model. Correlations were also computed using the model with selective hair-cell damage. Neural predictions revealed that envelope cross-correlation decreased with increased characteristic-frequency separation for all modulation ranges (with greater syllabic-envelope correlation than phonemic or periodicity). Syllabic envelope was highly correlated across many spectral channels, whereas phonemic and periodicity envelopes were correlated mainly between adjacent channels. Outer-hair-cell impairment increased the degree of cross-channel correlation for phonemic and periodicity ranges for speech in quiet and in noise, thereby reducing the number of independent neural information channels for envelope coding. In contrast, outer-hair-cell impairment was predicted to decrease cross-channel correlation for syllabic envelopes in noise, which may partially account for the reduced ability of hearing-impaired listeners to segregate speech in complex backgrounds.
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Affiliation(s)
- Jayaganesh Swaminathan
- Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana 47907-2038, USA.
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Contribution of spectral cues to mandarin lexical tone recognition in normal-hearing and hearing-impaired Mandarin Chinese speakers. Ear Hear 2011; 32:97-103. [PMID: 20625301 DOI: 10.1097/aud.0b013e3181ec5c28] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the contribution of spectral fine structure and spectral envelope cues to recognition of Mandarin lexical tones in normal-hearing and sensorineural hearing-impaired Mandarin-speaking listeners. DESIGN Four groups of subjects participated in the study, including 20 normal-hearing, 20 moderately, 20 moderately to severely, and 8 severely hearing-impaired listeners. The original speech materials consisted of 16 sets of Mandarin monosyllables spoken by a male and a female. Each monosyllable had four tonal patterns, resulting in a total of 64 combinations of consonants, vowels, and tones. A Linear Predictive Coding (LPC) algorithm was used to create two sets of synthesized materials, including 128 tokens with the original spectral fine structure mixed with the spectral envelope from a different tone, as well as 128 tokens with noise fine structure and the original spectral envelope. All subjects participated in tone recognition tests using the two sets of chimeric tone tokens. Oral responses to tones were recorded and scored as percent correct. RESULTS Hearing-impaired listeners could take advantage of spectral fine structure in the recognition of lexical tones, but with increasing hearing loss, the ability of hearing-impaired listeners to recognize tones became worse, especially for severely hearing-impaired listeners. Hearing-impaired listeners showed significant differences in tone recognition between the male and female voices. Tone 3 was the easiest tone to perceive, followed by tone 2, whereas tones 1 and 4 were hard for all subjects, particularly when only the spectral envelope cue was available. Hearing-impaired listeners showed a significantly lower level of lexical tone recognition than normal-hearing listeners when using spectral envelope cues in comparison with normal-hearing listeners. CONCLUSIONS These results demonstrate that the spectral fine structure cue dominates lexical tone recognition for all subjects. Listeners with sensorineural hearing impairment showed reduced ability in the recognition of lexical tones using both spectral fine structure and spectral envelope cues, which may result from their impaired auditory spectral resolution.
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Strydom T, Hanekom JJ. An analysis of the effects of electrical field interaction with an acoustic model of cochlear implants. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:2213-2226. [PMID: 21476676 DOI: 10.1121/1.3518761] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Electrical field interaction caused by current spread in a cochlear implant was modeled in an explicit way in an acoustic model (the SPREAD model) presented to six listeners with normal hearing. The typical processing of cochlear implants was modeled more closely than in traditional acoustic models by careful selection of parameters related to current spread or parameters that could amplify the electrical field interactions caused by current spread. These parameters were the insertion depth, electrode spacing, electrical dynamic range, and dynamic range compression function. The hypothesis was that current spread could account for the asymptote in performance in speech intelligibility experiments observed at around seven stimulation channels in a number of cochlear implant studies. Speech intelligibility for sentences, vowels, and consonants at three noise levels (SNR of +15 dB, +10 dB, and +5 dB) was measured as a function of the number of spectral channels (4, 7, and 16). The SPREAD model appears to explain the asymptote in speech intelligibility at seven channels for all noise levels for all speech material used in this study. It is shown that the compressive amplitude mapping used in cochlear implants can have a detrimental effect on the number of effective channels.
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Affiliation(s)
- Trudie Strydom
- Department of Electrical, Electronic and Computer Engineering, University of Pretoria, Pretoria, Gauteng 0002, South Africa
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Strydom T, Hanekom JJ. The performance of different synthesis signals in acoustic models of cochlear implants. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:920-933. [PMID: 21361449 DOI: 10.1121/1.3518760] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Synthesis (carrier) signals in acoustic models embody assumptions about perception of auditory electric stimulation. This study compared speech intelligibility of consonants and vowels processed through a set of nine acoustic models that used Spectral Peak (SPEAK) and Advanced Combination Encoder (ACE)-like speech processing, using synthesis signals which were representative of signals used previously in acoustic models as well as two new ones. Performance of the synthesis signals was determined in terms of correspondence with cochlear implant (CI) listener results for 12 attributes of phoneme perception (consonant and vowel recognition; F1, F2, and duration information transmission for vowels; voicing, manner, place of articulation, affrication, burst, nasality, and amplitude envelope information transmission for consonants) using four measures of performance. Modulated synthesis signals produced the best correspondence with CI consonant intelligibility, while sinusoids, narrow noise bands, and varying noise bands produced the best correspondence with CI vowel intelligibility. The signals that performed best overall (in terms of correspondence with both vowel and consonant attributes) were modulated and unmodulated noise bands of varying bandwidth that corresponded to a linearly varying excitation width of 0.4 mm at the apical to 8 mm at the basal channels.
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Affiliation(s)
- Trudie Strydom
- Department of Electrical, Electronic, and Computer Engineering, University of Pretoria, Pretoria 0002, South Africa
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Ardoint M, Sheft S, Fleuriot P, Garnier S, Lorenzi C. Perception of temporal fine-structure cues in speech with minimal envelope cues for listeners with mild-to-moderate hearing loss. Int J Audiol 2011; 49:823-31. [PMID: 20666687 DOI: 10.3109/14992027.2010.492402] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The contribution of temporal fine-structure (TFS) cues to consonant identification was compared for seven young adults with normal hearing and five young adults with mild-to-moderate hearing loss and flat, high- or low-frequency gently sloping audiograms. Nonsense syllables were degraded using two schemes (PM: phase modulation; FM: frequency modulation) designed to remove temporal envelope (E) cues while preserving TFS cues in 16 0.35-octave-wide frequency bands spanning the range of 80 to 8020 Hz. For both schemes, hearing-impaired listeners performed significantly above chance level (PM: 36%; FM: 31%; chance level: 6.25%), but more poorly than normal-hearing listeners (PM: 80%; FM: 65%). Three hearing-impaired listeners showed normal or near-normal reception of nasality information. These results indicate that for mild to moderate levels of hearing loss, cochlear damage reduces but does not abolish the ability to use the TFS cues of speech. The deficits observed for both schemes in hearing-impaired listeners suggest involvement of factors other than only poor reconstruction of temporal envelope from temporal fine structure.
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Affiliation(s)
- Marine Ardoint
- Laboratoire de Psychologie de la Perception, CNRS, Universite Paris Descartes, Ecole Normale Superieure, Paris, France.
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Healy EW, Carson KA. Influence of broad auditory tuning on across-frequency integration of speech patterns. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2010; 53:1087-95. [PMID: 20689025 PMCID: PMC2954411 DOI: 10.1044/1092-4388(2010/09-0185)] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
PURPOSE The purpose of the present study was to assess whether diminished tolerance for disruptions to across-frequency timing in listeners with hearing impairment can be attributed to broad auditory tuning. METHOD In 2 experiments in which random assignment was used, sentences were represented as 3 noise bands centered at 530, 1500, and 4243 Hz, which were amplitude modulated by 3 corresponding narrow speech bands. To isolate broad tuning from other influences of hearing impairment, listeners with normal hearing (45 in Experiment 1 and 30 in Experiment 2) were presented with these vocoder stimuli, having carrier band filter slopes of 12, 24, and 192 dB/octave. These speech patterns were presented in synchrony and with between-band asynchronies up to 40 ms. RESULTS Mean intelligibility scores were reduced in conditions of severe, but not moderate, simulated broadening. Although scores fell as asynchrony increased, the steeper drop in performance characteristic of listeners with hearing impairment tested previously was not observed in conditions of simulated broadening. CONCLUSIONS The intolerance for small across-frequency asynchronies observed previously does not appear attributable to broad tuning. Instead, the present data suggest that the across-frequency processing mechanism in at least some listeners with hearing impairment might be less robust to this type of degradation.
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Affiliation(s)
- Eric W Healy
- Department of Speech and Hearing Science, The Ohio State University, Pressey Hall, Room 110, 1070 Carmack Road, Columbus, OH 43210, USA.
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Envelope coding in auditory nerve fibers following noise-induced hearing loss. J Assoc Res Otolaryngol 2010; 11:657-73. [PMID: 20556628 DOI: 10.1007/s10162-010-0223-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 05/25/2010] [Indexed: 10/19/2022] Open
Abstract
Recent perceptual studies suggest that listeners with sensorineural hearing loss (SNHL) have a reduced ability to use temporal fine-structure cues, whereas the effects of SNHL on temporal envelope cues are generally thought to be minimal. Several perceptual studies suggest that envelope coding may actually be enhanced following SNHL and that this effect may actually degrade listening in modulated maskers (e.g., competing talkers). The present study examined physiological effects of SNHL on envelope coding in auditory nerve (AN) fibers in relation to fine-structure coding. Responses were compared between anesthetized chinchillas with normal hearing and those with a mild-moderate noise-induced hearing loss. Temporal envelope coding of narrowband-modulated stimuli (sinusoidally amplitude-modulated tones and single-formant stimuli) was quantified with several neural metrics. The relative strength of envelope and fine-structure coding was compared using shuffled correlogram analyses. On average, the strength of envelope coding was enhanced in noise-exposed AN fibers. A high degree of enhanced envelope coding was observed in AN fibers with high thresholds and very steep rate-level functions, which were likely associated with severe outer and inner hair cell damage. Degradation in fine-structure coding was observed in that the transition between AN fibers coding primarily fine structure or envelope occurred at lower characteristic frequencies following SNHL. This relative fine-structure degradation occurred despite no degradation in the fundamental ability of AN fibers to encode fine structure and did not depend on reduced frequency selectivity. Overall, these data suggest the need to consider the relative effects of SNHL on envelope and fine-structure coding in evaluating perceptual deficits in temporal processing of complex stimuli.
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Feng Y, Yin S, Wang J. Deterioration of cortical responses to amplitude modulations of low-frequency carriers after high-frequency cochlear lesion in guinea pigs. Int J Audiol 2010; 49:228-37. [DOI: 10.3109/14992020903280153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Başkent D, Eiler CL, Edwards B. Phonemic restoration by hearing-impaired listeners with mild to moderate sensorineural hearing loss. Hear Res 2010; 260:54-62. [DOI: 10.1016/j.heares.2009.11.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/08/2009] [Accepted: 11/10/2009] [Indexed: 11/28/2022]
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The effects of cochlear implant electrode deactivation on speech perception and in predicting device failure. Otol Neurotol 2009; 30:7-13. [PMID: 18833018 DOI: 10.1097/mao.0b013e31818a08ba] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To examine speech perception outcomes as related to a reduction in the number of functional electrodes postimplantation and to determine the effect of electrode reduction on subsequent device failure. STUDY DESIGN Retrospective review. SETTING Tertiary academic referral center. PATIENTS Of 1,520 children and adults with full insertions of the Advanced Bionics, Med El, and Nucleus devices, 15 (1%) were patients. Patients were included in the study if all electrodes were functional at initial stimulation, but the number of electrodes in use was subsequently reduced at follow-up programming sessions. Exclusion criteria included partial and split-array electrode insertions. INTERVENTION(S) Patients with bilateral severe to profound sensorineural hearing loss underwent either unilateral or bilateral cochlear implantation. MAIN OUTCOME MEASURE(S) Postimplantation speech perception tests obtained with a full complement of functional electrodes were performed and the results compared to those obtained with 1 or more electrodes removed from the user program. Electrode deactivation was also correlated with device failure. RESULTS AND CONCLUSION The results of this study indicate that deactivation of cochlear implant electrodes is relatively uncommon, and although the deactivation does not have a direct influence on speech performance outcomes, the loss of 5 or more electrodes can suggest impending device failure. Additionally, those patients with electrode deactivation coupled with a decline in speech perception scores should also be considered at risk for device failure.
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Lorenzi C, Debruille L, Garnier S, Fleuriot P, Moore BCJ. Abnormal processing of temporal fine structure in speech for frequencies where absolute thresholds are normal. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2009; 125:27-30. [PMID: 19173391 DOI: 10.1121/1.2939125] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The identification of nonsense syllables that were lowpass filtered at 1.5 kHz was compared for subjects with normal hearing and subjects with mild-to-severe hearing loss at high frequencies but with normal or near-normal hearing at low frequencies. Absolute thresholds were mostly within the normal range (<20 dB hearing level) for both groups for frequencies below 1.5 kHz. Performance was assessed with intact speech, speech that had been processed to preserve only temporal envelope cues in a few frequency bands (E speech), and speech that had been processed to remove envelope cues as far as possible while preserving temporal fine structure cues, again in a few frequency bands (TFS speech). For the intact speech and E speech, the hearing-impaired subjects performed slightly more poorly than the normal-hearing subjects, but this effect was significant only for the intact speech. For the TFS speech, the hearing-impaired subjects performed significantly more poorly than the normal-hearing subjects, with 12 out of 16 of the former performing at chance. The results indicate that, for people with hearing loss at medium to high frequencies, the processing of the TFS of speech can be degraded for frequencies where absolute thresholds are within the normal range.
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Affiliation(s)
- Christian Lorenzi
- Equipe Audition, LPP CNRS, Universite Paris Descartes, and DEC, Ecole Normale Superieure, Paris, France.
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Li X, Ning Z, Brashears R, Rife K. Relative Contributions of Spectral and Temporal Cues for Speech Recognition in Patients with Sensorineural Hearing Loss. J Otol 2008. [DOI: 10.1016/s1672-2930(08)50019-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Stone MA, Füllgrabe C, Moore BCJ. Benefit of high-rate envelope cues in vocoder processing: effect of number of channels and spectral region. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2008; 124:2272-82. [PMID: 19062865 DOI: 10.1121/1.2968678] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In cochlear implants, or vocoder simulations of cochlear implants, the transmission of envelope cues at high rates (related to voice fundamental frequency, f0) may be limited by the widths of the filters used to form the channels and/or by the cutoff frequency, f(lp), of the low-pass filters used for envelope extraction. The effect of varying f(lp) in tone and noise vocoders was investigated for channel numbers, N, from 6 to 18. As N increased, the widths of the channels decreased. The value of f(lp) was 45 Hz (envelope or "E" filter), or 180 Hz (pitch or "P" filter). The following combinations of cutoff frequencies were used for channels below and above 1500 Hz, respectively: EE, PE, EP, and PP. Results from a competing-talker task showed that the tone vocoder led to better intelligibility than the noise vocoder. The PP condition led to the best intelligibility and the EE condition to the worst. For N=6, intelligibility was better for condition PE than for condition EP. For N=18, the reverse was true. The results indicate that the channel bandwidths can compromise the transmission of f0-related envelope information, and suggest that vocoder simulations of cochlear-implant processing have limitations.
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Affiliation(s)
- Michael A Stone
- Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, United Kingdom.
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