The Experts below are selected from a list of 56436 Experts worldwide ranked by ideXlab platform
Fan Gang Zeng - One of the best experts on this subject based on the ideXlab platform.
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Electro-tactile stimulation enhances Cochlear Implant speech recognition in noise
Scientific Reports, 2017Co-Authors: Juan Huang, Benjamin Sheffield, Payton Lin, Fan Gang ZengAbstract:For Cochlear Implant users, combined electro-acoustic stimulation (EAS) significantly improves the performance. However, there are many more users who do not have any functional residual acoustic hearing at low frequencies. Because tactile sensation also operates in the same low frequencies (
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development and evaluation of the nurotron 26 electrode Cochlear Implant system
Hearing Research, 2015Co-Authors: Fan Gang Zeng, Qian Jie Fu, Stephen J Rebscher, Hongbin Chen, Lichuan Ping, Haihong Feng, Shiming Yang, Shusheng Gong, Beibei Yang, Houyong KangAbstract:Although the Cochlear Implant has been widely acknowledged as the most successful neural prosthesis, only a fraction of hearing-impaired people who can potentially benefit from a Cochlear Implant have actually received one due to its limited awareness, accessibility, and affordability. To help overcome these limitations, a 26-electrode Cochlear Implant has been developed to receive China's Food and Drug Administration (CFDA) approval in 2011 and Conformite Europeenne (CE) Marking in 2012. The present article describes design philosophy, system specification, and technical verification of the Nurotron device, which includes advanced digital signal processing and 4 current sources with multiple amplitude resolutions that not only are compatible with perceptual capability but also allow interleaved or simultaneous stimulation. The article also presents 3-year longitudinal evaluation data from 60 human subjects who have received the Nurotron device. The objective measures show that electrode impedance decreased within the first month of device use, but was stable until a slight increase at the end of two years. The subjective loudness measures show that electric stimulation threshold was stable while the maximal comfort level increased over the 3 years. Mandarin sentence recognition increased from the pre-surgical 0%-correct score to a plateau of about 80% correct with 6-month use of the device. Both indirect and direct comparisons indicate indistinguishable performance differences between the Nurotron system and other commercially available devices. The present 26-electrode Cochlear Implant has already helped to lower the price of Cochlear Implantation in China and will likely contribute to increased Cochlear Implant access and success in the rest of the world. This article is part of a Special Issue entitled .
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Comparison of bimodal and bilateral Cochlear Implant users on speech recognition with competing talker, music perception, affective prosody discrimination, and talker identification
Ear and Hearing, 2011Co-Authors: Helen E. Cullington, Fan Gang ZengAbstract:Despite excellent performance in speech recognition in quiet, most Cochlear Implant users have great difficulty with speech recognition in noise, music perception, identifying tone of voice, and discriminating different talkers. This may be partly due to the pitch coding in Cochlear Implant speech processing. Most current speech processing strategies use only the envelope information; the temporal fine structure is discarded. One way to improve electric pitch perception is to use residual acoustic hearing via a hearing aid on the nonImplanted ear (bimodal hearing). This study aimed to test the hypothesis that bimodal users would perform better than bilateral Cochlear Implant users on tasks requiring good pitch perception.
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Encoding frequency modulation to improve Cochlear Implant performance in noise
IEEE Transactions on Biomedical Engineering, 2005Co-Authors: Kai Bao Nie, Ginger S. Stickney, Fan Gang ZengAbstract:Different from traditional Fourier analysis, a signal can be decomposed into amplitude and frequency modulation components. The speech processing strategy in most modern Cochlear Implants only extracts and encodes amplitude modulation in a limited number of frequency bands. While amplitude modulation encoding has allowed Cochlear Implant users to achieve good speech recognition in quiet, their performance in noise is severely compromised. Here, we propose a novel speech processing strategy that encodes both amplitude and frequency modulations in order to improve Cochlear Implant performance in noise. By removing the center frequency from the subband signals and additionally limiting the frequency modulation's range and rate, the present strategy transforms the fast-varying temporal fine structure into a slowly varying frequency modulation signal. As a first step, we evaluated the potential contribution of additional frequency modulation to speech recognition in noise via acoustic simulations of the Cochlear Implant. We found that while amplitude modulation from a limited number of spectral bands is sufficient to support speech recognition in quiet, frequency modulation is needed to support speech recognition in noise. In particular, improvement by as much as 71 percentage points was observed for sentence recognition in the presence of a competing voice. The present result strongly suggests that frequency modulation be extracted and encoded to improve Cochlear Implant performance in realistic listening situations. We have proposed several implementation methods to stimulate further investigation. Index Terms-Amplitude modulation, Cochlear Implant, fine structure, frequency modulation, signal processing, speech recognition, temporal envelope.
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encoding frequency modulation to improve Cochlear Implant performance in noise
IEEE Transactions on Biomedical Engineering, 2005Co-Authors: Ginger S. Stickney, Fan Gang ZengAbstract:Different from traditional Fourier analysis, a signal can be decomposed into amplitude and frequency modulation components. The speech processing strategy in most modern Cochlear Implants only extracts and encodes amplitude modulation in a limited number of frequency bands. While amplitude modulation encoding has allowed Cochlear Implant users to achieve good speech recognition in quiet, their performance in noise is severely compromised. Here, we propose a novel speech processing strategy that encodes both amplitude and frequency modulations in order to improve Cochlear Implant performance in noise. By removing the center frequency from the subband signals and additionally limiting the frequency modulation's range and rate, the present strategy transforms the fast-varying temporal fine structure into a slowly varying frequency modulation signal. As a first step, we evaluated the potential contribution of additional frequency modulation to speech recognition in noise via acoustic simulations of the Cochlear Implant. We found that while amplitude modulation from a limited number of spectral bands is sufficient to support speech recognition in quiet, frequency modulation is needed to support speech recognition in noise. In particular, improvement by as much as 71 percentage points was observed for sentence recognition in the presence of a competing voice. The present result strongly suggests that frequency modulation be extracted and encoded to improve Cochlear Implant performance in realistic listening situations. We have proposed several implementation methods to stimulate further investigation.
Bruce J Gantz - One of the best experts on this subject based on the ideXlab platform.
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subtotal petrosectomy and mastoid obliteration in adult and pediatric Cochlear Implant recipients
Otology & Neurotology, 2013Co-Authors: Christopher F Baranano, Bruce J Gantz, Jonathan C Kopelovich, Camille C Dunn, Marlan R HansenAbstract:ObjectiveTo investigate the effect of subtotal petrosectomy and mastoid obliteration (SPMO) on the overall success of adult and pediatric Cochlear Implant (CI) recipients.Study DesignRetrospective case series.SettingTertiary care referral center.PatientsThirty-nine ears in 36 patients (23 adults and
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changes in pitch with a Cochlear Implant over time
Jaro-journal of The Association for Research in Otolaryngology, 2007Co-Authors: Lina A J Reiss, Christopher W Turner, Sheryl R Erenberg, Bruce J GantzAbstract:In the normal auditory system, the perceived pitch of a tone is closely linked to the Cochlear place of vibration. It has generally been assumed that high-rate electrical stimulation by a Cochlear Implant electrode also evokes a pitch sensation corresponding to the electrode’s Cochlear place (“place” code) and stimulation rate (“temporal” code). However, other factors may affect electric pitch sensation, such as a substantial loss of nearby nerve fibers or even higher-level perceptual changes due to experience. The goals of this study were to measure electric pitch sensations in hybrid (short-electrode) Cochlear Implant patients and to examine which factors might contribute to the perceived pitch. To look at effects of experience, electric pitch sensations were compared with acoustic tone references presented to the non-Implanted ear at various stages of Implant use, ranging from hookup to 5 years. Here, we show that electric pitch perception often shifts in frequency, sometimes by as much as two octaves, during the first few years of Implant use. Additional pitch measurements in more recently Implanted patients at shorter time intervals up to 1 year of Implant use suggest two likely contributions to these observed pitch shifts: intersession variability (up to one octave) and slow, systematic changes over time. We also found that the early pitch sensations for a constant electrode location can vary greatly across subjects and that these variations are strongly correlated with speech reception performance. Specifically, patients with an early low-pitch sensation tend to perform poorly with the Implant compared to those with an early high-pitch sensation, which may be linked to less nerve survival in the basal end of the cochlea in the low-pitch patients. In contrast, late pitch sensations show no correlation with speech perception. These results together suggest that early pitch sensations may more closely reflect peripheral innervation patterns, while later pitch sensations may reflect higher-level, experience-dependent changes. These pitch shifts over time not only raise questions for strict place-based theories of pitch perception, but also imply that experience may have a greater influence on Cochlear Implant perception than previously thought.
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preservation of hearing in Cochlear Implant surgery advantages of combined electrical and acoustical speech processing
Laryngoscope, 2005Co-Authors: Christopher W Turner, Bruce J Gantz, Kate Gfeller, Mary W LowderAbstract:Objectives/Hypothesis: This study documents the importance of preserving residual low-frequency acoustic hearing as those with more residual hearing are selected for Cochlear Implantation. Surgical strategies used for hearing preservation with a short hybrid Cochlear Implant are outlined. The benefits of preserved residual low-frequency hearing, improved word understanding in noise, and music appreciation are described. Study Design: Multicenter, prospective, single-subject design. Methods: Records were reviewed of 21 individuals participating in an Food and Drug Administration (FDA) feasibility clinical trial who have received an Iowa/Nucleus 10 mm electrode. A second group of subjects receiving Implants at the University of Iowa that have used the 10 mm device between 2 years and 6 months were also reviewed. Outcome measures included standardized tests of monosyllabic word understanding, spondees in noise, and common melody recognition. Results: Lowfrequency hearing was maintained in all individuals immediately postoperative. One subject lost hearing at 2.5 months postoperative after a viral infection. The group has averaged a loss of 9 dB low-frequency acoustic hearing between 125 and 1,000 Hz. Monosyllabic word understanding scores at 6 months for a group being followed for an FDA clinical trial using the Implant plus hearing aids was 69% correct. For the long-term group receiving Implants at Iowa, monosyllabic word understanding in those who have used the device between 6 months and 2 years is 79%. Other important findings include improved recognition of speech in noise (9 dB improvement) as compared with standard Cochlear Implant recipients who were matched for speech recognition in quiet and near normal recognition of common melodies. Conclusion: The surgical strategies outlined have been successful in preservation of low-frequency hearing in 96% of individuals. Combined electrical and acoustical speech processing has enabled this group of volunteers to gain improved word understanding as compared with their preoperative hearing with bilateral hearing aids and a group of individuals receiving a standard Cochlear Implant with similar experience with their device. The improvement of speech in noise and melody recognition is attributed to the ability to distinguish fine pitch differences as the result of preserved residual low-frequency acoustic hearing. Preservation of low-frequency acoustic hearing is important for improving speech in noise and music appreciation for the hearing impaired, both of which are important in real-life situations. Key Words: Hearing Preservation, Cochlear Implant, hybrid Cochlear Implant, hearing in noise. Laryngoscope, 115:796–802, 2005
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Speech recognition in noise for Cochlear Implant listeners: Benefits of residual acoustic hearing
The Journal of the Acoustical Society of America, 2004Co-Authors: Christopher W Turner, Corina Vidal, Amy Behrens, Bruce J Gantz, Belinda A HenryAbstract:The purpose of this study was to explore the potential advantages, both theoretical and applied, of preserving low-frequency acoustic hearing in Cochlear Implant patients. Several hypotheses are presented that predict that residual low-frequency acoustic hearing along with electric stimulation for high frequencies will provide an advantage over traditional long-electrode Cochlear Implants for the recognition of speech in competing backgrounds. A simulation experiment in normal-hearing subjects demonstrated a clear advantage for preserving low-frequency residual acoustic hearing for speech recognition in a background of other talkers, but not in steady noise. Three subjects with an Implanted ''short-electrode'' Cochlear Implant and preserved low-frequency acoustic hearing were also tested on speech recognition in the same competing backgrounds and compared to a larger group of traditional Cochlear Implant users. Each of the three short-electrode subjects performed better than any of the traditional long-electrode Implant subjects for speech recognition in a background of other talkers, but not in steady noise, in general agreement with the simulation studies. When compared to a subgroup of traditional Implant users matched according to speech recognition ability in quiet, the short-electrode patients showed a 9-dB advantage in the multitalker background. These experiments provide strong preliminary support for retaining residual low-frequency acoustic hearing in Cochlear Implant patients. The results are consistent with the idea that better perception of voice pitch, which can aid in separating voices in a background of other talkers, was responsible for this advantage.
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residual speech recognition and Cochlear Implant performance effects of Implantation criteria
American Journal of Otology, 1999Co-Authors: Jay T Rubinstein, Richard S Tyler, Wendy S Parkinson, Bruce J GantzAbstract:Objective:This study aimed to determine the effects of preoperative speech reception on postoperative speech recognition with a Cochlear Implant and to develop a statistical index allowing prediction of postoperative speech recognition before Implantation.Study Design:The study design was a retrospe
Qian Jie Fu - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of the nurotron 26 electrode Cochlear Implant system
Hearing Research, 2015Co-Authors: Fan Gang Zeng, Qian Jie Fu, Stephen J Rebscher, Hongbin Chen, Lichuan Ping, Haihong Feng, Shiming Yang, Shusheng Gong, Beibei Yang, Houyong KangAbstract:Although the Cochlear Implant has been widely acknowledged as the most successful neural prosthesis, only a fraction of hearing-impaired people who can potentially benefit from a Cochlear Implant have actually received one due to its limited awareness, accessibility, and affordability. To help overcome these limitations, a 26-electrode Cochlear Implant has been developed to receive China's Food and Drug Administration (CFDA) approval in 2011 and Conformite Europeenne (CE) Marking in 2012. The present article describes design philosophy, system specification, and technical verification of the Nurotron device, which includes advanced digital signal processing and 4 current sources with multiple amplitude resolutions that not only are compatible with perceptual capability but also allow interleaved or simultaneous stimulation. The article also presents 3-year longitudinal evaluation data from 60 human subjects who have received the Nurotron device. The objective measures show that electrode impedance decreased within the first month of device use, but was stable until a slight increase at the end of two years. The subjective loudness measures show that electric stimulation threshold was stable while the maximal comfort level increased over the 3 years. Mandarin sentence recognition increased from the pre-surgical 0%-correct score to a plateau of about 80% correct with 6-month use of the device. Both indirect and direct comparisons indicate indistinguishable performance differences between the Nurotron system and other commercially available devices. The present 26-electrode Cochlear Implant has already helped to lower the price of Cochlear Implantation in China and will likely contribute to increased Cochlear Implant access and success in the rest of the world. This article is part of a Special Issue entitled .
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melodic contour identification by Cochlear Implant listeners
Ear and Hearing, 2007Co-Authors: John J. Galvin, Qian Jie Fu, Geraldine NogakiAbstract:Objective: While the Cochlear Implant provides many deaf patients with good speech understanding in quiet, music perception and appreciation with the Cochlear Implant remains a major challenge for most Cochlear Implant users. The present study investigated whether a closed-set melodic contour identification (MCI) task could be used to quantify Cochlear Implant users' ability to recognize musical melodies and whether MCI performance could be improved with moderate auditory training. The present study also compared MCI performance with familiar melody identification (FMI) performance, with and without MCI training. Methods: For the MCI task, test stimuli were melodic contours composed of 5 notes of equal duration whose frequencies corresponded to musical intervals. The interval between successive notes in each contour was varied between 1 and 5 semitones; the “root note” of the contours was also varied (A3, A4, and A5). Nine distinct musical patterns were generated for each interval and root note condition, resulting in a total of 135 musical contours. The identification of these melodic contours was measured in 11 Cochlear Implant users. FMI was also evaluated in the same subjects; recognition of 12 familiar melodies was tested with and without rhythm cues. MCI was also trained in 6 subjects, using custom software and melodic contours presented in a different frequency range from that used for testing. Results: Results showed that MCI recognition performance was highly variable among Cochlear Implant users, ranging from 14% to 91% correct. For most subjects, MCI performance improved as the number of semitones between successive notes was increased; performance was slightly lower for the A3 root note condition. Mean FMI performance was 58% correct when rhythm cues were preserved and 29% correct when rhythm cues were removed. Statistical analyses revealed no significant correlation between MCI performance and FMI performance (with or without rhythmic cues). However, MCI performance was significantly correlated with vowel recognition performance; FMI performance was not correlated with Cochlear Implant subjects' phoneme recognition performance. Preliminary results also showed that the MCI training improved all subjects' MCI performance; the improved MCI performance also generalized to improved FMI performance. Conclusions: Preliminary data indicate that the closed-set MCI task is a viable approach toward quantifying an important component of Cochlear Implant users' music perception. The improvement in MCI performance and generalization to FMI performance with training suggests that MCI training may be useful for improving Cochlear Implant users' music perception and appreciation; such training may be necessary to properly evaluate patient performance, as acute measures may underestimate the amount of musical information transmitted by the Cochlear Implant device and received by Cochlear Implant listeners.
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Cochlear Implants Special Issue Article: Vocal Emotion Recognition by Normal-Hearing Listeners and Cochlear Implant Users
Trends in Amplification, 2007Co-Authors: Xin Luo, Qian Jie Fu, John J. GalvinAbstract:The present study investigated the ability of normal-hearing listeners and Cochlear Implant users to recognize vocal emotions. Sentences were produced by 1 male and 1 female talker according to 5 target emotions: angry, anxious, happy, sad, and neutral. Overall amplitude differences between the stimuli were either preserved or normalized. In experiment 1, vocal emotion recognition was measured in normal-hearing and Cochlear Implant listeners; Cochlear Implant subjects were tested using their clinically assigned processors. When overall amplitude cues were preserved, normal-hearing listeners achieved near-perfect performance, whereas listeners with Cochlear Implant recognized less than half of the target emotions. Removing the overall amplitude cues significantly worsened mean normal-hearing and Cochlear Implant performance. In experiment 2, vocal emotion recognition was measured in listeners with Cochlear Implant as a function of the number of channels (from 1 to 8) and envelope filter cutoff frequency (50 vs 400 Hz) in experimental speech processors. In experiment 3, vocal emotion recognition was measured in normal-hearing listeners as a function of the number of channels (from 1 to 16) and envelope filter cutoff frequency (50 vs 500 Hz) in acoustic Cochlear Implant simulations. Results from experiments 2 and 3 showed that both Cochlear Implant and normal-hearing performance significantly improved as the number of channels or the envelope filter cutoff frequency was increased. The results suggest that spectral, temporal, and overall amplitude cues each contribute to vocal emotion recognition. The poorer Cochlear Implant performance is most likely attributable to the lack of salient pitch cues and the limited functional spectral resolution.
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noise susceptibility of Cochlear Implant users the role of spectral resolution and smearing
Jaro-journal of The Association for Research in Otolaryngology, 2005Co-Authors: Qian Jie Fu, Geraldine NogakiAbstract:The latest-generation Cochlear Implant devices provide many deaf patients with good speech recognition in quiet listening conditions. However, speech recognition deteriorates rapidly as the level of background noise increases. Previous studies have shown that, for Cochlear Implant users, the absence of fine spectro-temporal cues may contribute to poorer performance in noise, especially when the noise is dynamic (e.g., competing speaker or modulated noise). Here we report on sentence recognition by Cochlear Implant users and by normal-hearing subjects listening to an acoustic simulation of a Cochlear Implant, in the presence of steady or square-wave modulated speech-shaped noise. Implant users were tested using their everyday, clinically assigned speech processors. In the acoustic simulation, normal-hearing listeners were tested for different degrees of spectral resolution (16, eight, or four channels) and spectral smearing (carrier filter slopes of −24 or −6 dB/octave). For modulated noise, normal-hearing listeners experienced significant release from masking when the original, unprocessed speech was presented (which preserved the spectro-temporal fine structure), while Cochlear Implant users experienced no release from masking. As the spectral resolution was reduced, normal-hearing listeners’ release from masking gradually diminished. Release from masking was further reduced as the degree of spectral smearing increased. Interestingly, the mean speech recognition thresholds of Implant users were very close to those of normal-hearing subjects listening to four-channel spectrally smeared noise-band speech. Also, the best Cochlear Implant listeners performed like normal-hearing subjects listening to eight- to 16-channel spectrally smeared noise-band speech. These findings suggest that Implant users’ susceptibility to noise may be caused by the reduced spectral resolution and the high degree of spectral smearing associated with channel interaction. Efforts to improve the effective number of spectral channels as well as reduce channel interactions may improve Implant performance in noise, especially for temporally modulated noise.
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The role of spectral and temporal cues in voice gender discrimination by normal-hearing listeners and Cochlear Implant users
JARO - Journal of the Association for Research in Otolaryngology, 2004Co-Authors: Qian Jie Fu, Sherol Chinchilla, John J. GalvinAbstract:The present study investigated the relative importance of temporal and spectral cues in voice gender discrimination and vowel recognition by normal-hearing subjects listening to an acoustic simulation of Cochlear Implant speech processing and by Cochlear Implant users. In the simulation, the number of speech processing channels ranged from 4 to 32, thereby varying the spectral resolution; the cutoff frequencies of the channels' envelope filters ranged from 20 to 320 Hz, thereby manipulating the available temporal cues. For normal-hearing subjects, results showed that both voice gender discrimination and vowel recognition scores improved as the number of spectral channels was increased. When only 4 spectral channels were available, voice gender discrimination significantly improved as the envelope filter cutoff frequency was increased from 20 to 320 Hz. For all spectral conditions, increasing the amount of temporal information had no significant effect on vowel recognition. Both voice gender discrimination and vowel recognition scores were highly variable among Implant users. The performance of Cochlear Implant listeners was similar to that of normal-hearing subjects listening to comparable speech processing (4-8 spectral channels). The results suggest that both spectral and temporal cues contribute to voice gender discrimination and that temporal cues are especially important for Cochlear Implant users to identify the voice gender when there is reduced spectral resolution.
Ginger S. Stickney - One of the best experts on this subject based on the ideXlab platform.
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encoding frequency modulation to improve Cochlear Implant performance in noise
IEEE Transactions on Biomedical Engineering, 2005Co-Authors: Ginger S. Stickney, Fan Gang ZengAbstract:Different from traditional Fourier analysis, a signal can be decomposed into amplitude and frequency modulation components. The speech processing strategy in most modern Cochlear Implants only extracts and encodes amplitude modulation in a limited number of frequency bands. While amplitude modulation encoding has allowed Cochlear Implant users to achieve good speech recognition in quiet, their performance in noise is severely compromised. Here, we propose a novel speech processing strategy that encodes both amplitude and frequency modulations in order to improve Cochlear Implant performance in noise. By removing the center frequency from the subband signals and additionally limiting the frequency modulation's range and rate, the present strategy transforms the fast-varying temporal fine structure into a slowly varying frequency modulation signal. As a first step, we evaluated the potential contribution of additional frequency modulation to speech recognition in noise via acoustic simulations of the Cochlear Implant. We found that while amplitude modulation from a limited number of spectral bands is sufficient to support speech recognition in quiet, frequency modulation is needed to support speech recognition in noise. In particular, improvement by as much as 71 percentage points was observed for sentence recognition in the presence of a competing voice. The present result strongly suggests that frequency modulation be extracted and encoded to improve Cochlear Implant performance in realistic listening situations. We have proposed several implementation methods to stimulate further investigation.
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Encoding frequency modulation to improve Cochlear Implant performance in noise
IEEE Transactions on Biomedical Engineering, 2005Co-Authors: Kai Bao Nie, Ginger S. Stickney, Fan Gang ZengAbstract:Different from traditional Fourier analysis, a signal can be decomposed into amplitude and frequency modulation components. The speech processing strategy in most modern Cochlear Implants only extracts and encodes amplitude modulation in a limited number of frequency bands. While amplitude modulation encoding has allowed Cochlear Implant users to achieve good speech recognition in quiet, their performance in noise is severely compromised. Here, we propose a novel speech processing strategy that encodes both amplitude and frequency modulations in order to improve Cochlear Implant performance in noise. By removing the center frequency from the subband signals and additionally limiting the frequency modulation's range and rate, the present strategy transforms the fast-varying temporal fine structure into a slowly varying frequency modulation signal. As a first step, we evaluated the potential contribution of additional frequency modulation to speech recognition in noise via acoustic simulations of the Cochlear Implant. We found that while amplitude modulation from a limited number of spectral bands is sufficient to support speech recognition in quiet, frequency modulation is needed to support speech recognition in noise. In particular, improvement by as much as 71 percentage points was observed for sentence recognition in the presence of a competing voice. The present result strongly suggests that frequency modulation be extracted and encoded to improve Cochlear Implant performance in realistic listening situations. We have proposed several implementation methods to stimulate further investigation. Index Terms-Amplitude modulation, Cochlear Implant, fine structure, frequency modulation, signal processing, speech recognition, temporal envelope.
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Cochlear Implant speech recognition with speech maskers
Journal of the Acoustical Society of America, 2004Co-Authors: Ginger S. Stickney, Ruth Litovsky, Fan Gang Zeng, Peter AssmannAbstract:Speech recognition performance was measured in normal-hearing and Cochlear-Implant listeners with maskers consisting of either steady-state speech-spectrum-shaped noise or a competing sentence. Target sentences from a male talker were presented in the presence of one of three competing talkers (same male, different male, or female) or speech-spectrum-shaped noise generated from this talker at several target-to-masker ratios. For the normal-hearing listeners, target-masker combinations were processed through a noise-excited vocoder designed to simulate a Cochlear Implant. With unprocessed stimuli, a normal-hearing control group maintained high levels of intelligibility down to target-to-masker ratios as low as 0 dB and showed a release from masking, producing better performance with single-talker maskers than with steady-state noise. In contrast, no masking release was observed in either Implant or normal-hearing subjects listening through an Implant simulation. The performance of the simulation and implan...
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Cochlear Implant speech recognition with speech maskers
The Journal of the Acoustical Society of America, 2004Co-Authors: Ginger S. Stickney, Ruth Litovsky, Fan Gang Zeng, Peter AssmannAbstract:Speech recognition performance was measured in normal-hearing and Cochlear-Implant listeners with maskers consisting of either steady-state speech-spectrum-shaped noise or a competing sentence. Target sentences from a male talker were presented in the presence of one of three competing talkers ͑same male, different male, or female͒ or speech-spectrum-shaped noise generated from this talker at several target-to-masker ratios. For the normal-hearing listeners, target-masker combinations were processed through a noise-excited vocoder designed to simulate a Cochlear Implant. With unprocessed stimuli, a normal-hearing control group maintained high levels of intelligibility down to target-to-masker ratios as low as 0 dB and showed a release from masking, producing better performance with single-talker maskers than with steady-state noise. In contrast, no masking release was observed in either Implant or normal-hearing subjects listening through an Implant simulation. The performance of the simulation and Implant groups did not improve when the single-talker masker was a different talker compared to the same talker as the target speech, as was found in the normal-hearing control. These results are interpreted as evidence for a significant role of informational masking and modulation interference in Cochlear Implant speech recognition with fluctuating maskers. This informational masking may originate from increased target-masker similarity when spectral resolution is reduced.
Charles J. Limb - One of the best experts on this subject based on the ideXlab platform.
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voice emotion perception and production in Cochlear Implant users
Hearing Research, 2017Co-Authors: Nicole T. Jiam, M. Caldwell, Mickael L. Deroche, Monita Chatterjee, Charles J. LimbAbstract:Abstract Voice emotion is a fundamental component of human social interaction and social development. Unfortunately, Cochlear Implant users are often forced to interface with highly degraded prosodic cues as a result of device constraints in extraction, processing, and transmission. As such, individuals with Cochlear Implants frequently demonstrate significant difficulty in recognizing voice emotions in comparison to their normal hearing counterparts. Cochlear Implant-mediated perception and production of voice emotion is an important but relatively understudied area of research. However, a rich understanding of the voice emotion auditory processing offers opportunities to improve upon CI biomedical design and to develop training programs benefiting CI performance. In this review, we will address the issues, current literature, and future directions for improved voice emotion processing in Cochlear Implant users.
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technological biological and acoustical constraints to music perception in Cochlear Implant users
Hearing Research, 2014Co-Authors: Charles J. LimbAbstract:Abstract Despite advances in technology, the ability to perceive music remains limited for many Cochlear Implant users. This paper reviews the technological, biological, and acoustical constraints that make music an especially challenging stimulus for Cochlear Implant users, while highlighting recent research efforts to overcome these shortcomings. The limitations of Cochlear Implant devices, which have been optimized for speech comprehension, become evident when applied to music, particularly with regards to inadequate spectral, fine-temporal, and dynamic range representation. Beyond the impoverished information transmitted by the device itself, both peripheral and central auditory nervous system deficits are seen in the presence of sensorineural hearing loss, such as auditory nerve degeneration and abnormal auditory cortex activation. These technological and biological constraints to effective music perception are further compounded by the complexity of the acoustical features of music itself that require the perceptual integration of varying rhythmic, melodic, harmonic, and timbral elements of sound. Cochlear Implant users not only have difficulty perceiving spectral components individually (leading to fundamental disruptions in perception of pitch, melody, and harmony) but also display deficits with higher perceptual integration tasks required for music perception, such as auditory stream segregation. Despite these current limitations, focused musical training programs, new assessment methods, and improvements in the representation and transmission of the complex acoustical features of music through technological innovation offer the potential for significant advancements in Cochlear Implant-mediated music perception. This article is part of a Special Issue entitled .