The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Andrew J Oxenham - One of the best experts on this subject based on the ideXlab platform.
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Pitch Discrimination with mixtures of three concurrent harmonic complexes
Journal of the Acoustical Society of America, 2019Co-Authors: Jackson Graves, Andrew J OxenhamAbstract:In natural listening contexts, especially in music, it is common to hear three or more simultaneous Pitches, but few empirical or theoretical studies have addressed how this is achieved. Place and pattern-recognition theories of Pitch require at least some harmonics to be spectrally resolved for Pitch to be extracted, but it is unclear how often such conditions exist when multiple complex tones are presented together. In three behavioral experiments, mixtures of three concurrent complexes were filtered into a single bandpass spectral region, and the relationship between the fundamental frequencies and spectral region was varied in order to manipulate the extent to which harmonics were resolved either before or after mixing. In experiment 1, listeners discriminated major from minor triads (a difference of 1 semitone in one note of the triad). In experiments 2 and 3, listeners compared the Pitch of a probe tone with that of a subsequent target, embedded within two other tones. All three experiments demonstrated above-chance performance, even in conditions where the combinations of harmonic components were unlikely to be resolved after mixing, suggesting that fully resolved harmonics may not be necessary to extract the Pitch from multiple simultaneous complexes.
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fundamental frequency Discrimination based on temporal envelope cues effects of bandwidth and interference
Journal of the Acoustical Society of America, 2018Co-Authors: Anahita H Mehta, Andrew J OxenhamAbstract:Both music and speech perception rely on hearing out one Pitch in the presence of others. Pitch Discrimination of narrowband sounds based only on temporal-envelope cues is rendered nearly impossible by introducing interferers in both normal-hearing listeners and cochlear-implant (CI) users. This study tested whether performance improves in normal-hearing listeners if the target is presented over a broad spectral region. The results indicate that performance is still strongly affected by spectrally remote interferers, despite increases in bandwidth, suggesting that envelope-based Pitch is unlikely to allow CI users to perceive Pitch when multiple harmonic sounds are presented at once.Both music and speech perception rely on hearing out one Pitch in the presence of others. Pitch Discrimination of narrowband sounds based only on temporal-envelope cues is rendered nearly impossible by introducing interferers in both normal-hearing listeners and cochlear-implant (CI) users. This study tested whether performance improves in normal-hearing listeners if the target is presented over a broad spectral region. The results indicate that performance is still strongly affected by spectrally remote interferers, despite increases in bandwidth, suggesting that envelope-based Pitch is unlikely to allow CI users to perceive Pitch when multiple harmonic sounds are presented at once.
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learning for Pitch and melody Discrimination in congenital amusia
Cortex, 2018Co-Authors: Kelly L Whiteford, Andrew J OxenhamAbstract:Congenital amusia is currently thought to be a life-long neurogenetic disorder in music perception, impervious to training in Pitch or melody Discrimination. This study provides an explicit test of whether amusic deficits can be reduced with training. Twenty amusics and 20 matched controls participated in four sessions of psychophysical training involving either pure-tone (500 Hz) Pitch Discrimination or a control task of lateralization (interaural level differences for bandpass white noise). Pure-tone Pitch Discrimination at low, medium, and high frequencies (500, 2000, and 8000 Hz) was measured before and after training (pretest and posttest) to determine the specificity of learning. Melody Discrimination was also assessed before and after training using the full Montreal Battery of Evaluation of Amusia, the most widely used standardized test to diagnose amusia. Amusics performed more poorly than controls in Pitch but not localization Discrimination, but both groups improved with practice on the trained stimuli. Learning was broad, occurring across all three frequencies and melody Discrimination for all groups, including those who trained on the non-Pitch control task. Following training, 11 of 20 amusics no longer met the global diagnostic criteria for amusia. A separate group of untrained controls (n = 20), who also completed melody Discrimination and pretest, improved by an equal amount as trained controls on all measures, suggesting that the bulk of learning for the control group occurred very rapidly from the pretest. Thirty-one trained participants (13 amusics) returned one year later to assess long-term maintenance of Pitch and melody Discrimination. On average, there was no change in performance between posttest and one-year follow-up, demonstrating that improvements on Pitch- and melody-related tasks in amusics and controls can be maintained. The findings indicate that amusia is not always a life-long deficit when using the current standard diagnostic criteria.
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further evidence that fundamental frequency difference limens measure Pitch Discrimination
Journal of the Acoustical Society of America, 2012Co-Authors: Christophe Micheyl, Claire Ryan, Andrew J OxenhamAbstract:Difference limens for complex tones (DLCs) that differ in F0 are widely regarded as a measure of periodicity-Pitch Discrimination. However, because F0 changes are inevitably accompanied by changes in the frequencies of the harmonics, DLCs may actually reflect the discriminability of individual components. To test this hypothesis, DLCs were measured for complex tones, the component frequencies of which were shifted coherently upward or downward by ΔF = 0%, 25%, 37.5%, or 50% of the F0, yielding fully harmonic (ΔF = 0%), strongly inharmonic (ΔF = 25%, 37.5%), or odd-harmonic (ΔF = 50%) tones. If DLCs truly reflect periodicity-Pitch discriminability, they should be larger (worse) for inharmonic tones than for harmonic and odd harmonic tones because inharmonic tones have a weaker Pitch. Consistent with this prediction, the results of two experiments showed a non-monotonic dependence of DLCs on ΔF, with larger DLCs for ΔF’s of ±25% or ±37.5% than for ΔF’s of 0 or ±50% of F0. These findings are consistent with ...
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further evidence that fundamental frequency difference limens measure Pitch Discrimination
Journal of the Acoustical Society of America, 2012Co-Authors: Christophe Micheyl, Claire Ryan, Andrew J OxenhamAbstract:Difference limens for complex tones (DLCs) that differ in F0 are widely regarded as a measure of periodicity-Pitch Discrimination. However, because F0 changes are inevitably accompanied by changes in the frequencies of the harmonics, DLCs may actually reflect the discriminability of individual components. To test this hypothesis, DLCs were measured for complex tones, the component frequencies of which were shifted coherently upward or downward by ΔF = 0%, 25%, 37.5%, or 50% of the F0, yielding fully harmonic (ΔF = 0%), strongly inharmonic (ΔF = 25%, 37.5%), or odd-harmonic (ΔF = 50%) tones. If DLCs truly reflect periodicity-Pitch discriminability, they should be larger (worse) for inharmonic tones than for harmonic and odd harmonic tones because inharmonic tones have a weaker Pitch. Consistent with this prediction, the results of two experiments showed a non-monotonic dependence of DLCs on ΔF, with larger DLCs for ΔF’s of ±25% or ±37.5% than for ΔF’s of 0 or ±50% of F0. These findings are consistent with models of Pitch perception that involve harmonic templates or with an autocorrelation-based model provided that more than just the highest peak in the summary autocorrelogram is taken into account.
Torsten Dau - One of the best experts on this subject based on the ideXlab platform.
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effect of musical training on Pitch Discrimination performance in older normal hearing and hearing impaired listeners
Proceedings of the International Symposium on Auditory and Audiological Research, 2017Co-Authors: Federica Bianchi, Torsten Dau, Sebastien SanturetteAbstract:Hearing-impaired (HI) listeners, as well as elderly listeners, typically have a reduced ability to discriminate the fundamental frequency (F0) of complex tones compared to young normal-hearing (NH) listeners. Several studies have shown that musical training, on the other hand, leads to improved F0-Discrimination performance for NH listeners. It is unclear whether a comparable effect of musical training occurs for listeners whose sensory encoding of F0 is degraded. To address this question, F0 Discrimination was investigated for three groups of listeners (14 young NH, 9 older NH and 10 HI listeners), each including musicians and non-musicians, using complex tones that differed in harmonic content. Musical training significantly improved F0 Discrimination for all groups of listeners, especially for complex tones containing low-numbered harmonics. In a second experiment, the sensitivity to temporal fine structure cues (TFS) was estimated in the same listeners. Although TFS cues were degraded for the two older groups of listeners, musicians showed better performance than non-musicians. Additionally, a significant correlation was obtained between F0-Discrimination performance and sensitivity to TFS cues for complex tones with low and intermediate harmonic numbers. These findings suggest that musical training may enhance both sensory encoding of TFS cues and F0 Discrimination in young and older listeners with or without hearing loss.
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subcortical and cortical correlates of Pitch Discrimination evidence for two levels of neuroplasticity in musicians
NeuroImage, 2017Co-Authors: Federica Bianchi, Jens Hjortkjaer, Sebastien Santurette, Robert J Zatorre, Hartwig R Siebner, Torsten DauAbstract:Musicians are highly trained to discriminate fine Pitch changes but the neural bases of this ability are poorly understood. It is unclear whether such training-dependent differences in Pitch processing arise already in the subcortical auditory system or are linked to more central stages. To address this question, we combined psychoacoustic testing with functional MRI to measure cortical and subcortical responses in musicians and non-musicians during a Pitch-Discrimination task. First, we estimated behavioral Pitch-Discrimination thresholds for complex tones with harmonic components that were either resolved or unresolved in the auditory system. Musicians outperformed non-musicians, showing lower Pitch-Discrimination thresholds in both conditions. The same participants underwent task-related functional MRI, while they performed a similar Pitch-Discrimination task. To account for the between-group differences in Pitch-Discrimination, task difficulty was adjusted to each individual's Pitch-Discrimination ability. Relative to non-musicians, musicians showed increased neural responses to complex tones with either resolved or unresolved harmonics especially in right-hemispheric areas, comprising the right superior temporal gyrus, Heschl's gyrus, insular cortex, inferior frontal gyrus, and in the inferior colliculus. Both subcortical and cortical neural responses predicted the individual Pitch-Discrimination performance. However, functional activity in the inferior colliculus correlated with differences in Pitch Discrimination across all participants, but not within the musicians group alone. Only neural activity in the right auditory cortex scaled with the fine Pitch-Discrimination thresholds within the musicians. These findings suggest two levels of neuroplasticity in musicians, whereby training-dependent changes in Pitch processing arise at the collicular level and are preserved and further enhanced in the right auditory cortex.
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complex tone Pitch Discrimination in listeners with sensorineural hearing loss
Trends in hearing, 2016Co-Authors: Federica Bianchi, Sebastien Santurette, Michal Fereczkowski, Johannes Zaar, Torsten DauAbstract:Physiological studies have shown that noise-induced sensorineural hearing loss (SNHL) enhances the amplitude of envelope coding in auditory-nerve fibers. As Pitch coding of unresolved complex tones is assumed to rely on temporal envelope coding mechanisms, this study investigated Pitch-Discrimination performance in listeners with SNHL. Pitch-Discrimination thresholds were obtained for 14 normal-hearing (NH) and 10 hearing-impaired (HI) listeners for sine-phase (SP) and random-phase (RP) complex tones. When all harmonics were unresolved, the HI listeners performed, on average, worse than NH listeners in the RP condition but similarly to NH listeners in the SP condition. The increase in Pitch-Discrimination performance for the SP relative to the RP condition (F0DL ratio) was significantly larger in the HI as compared with the NH listeners. Cochlear compression and auditory-filter bandwidths were estimated in the same listeners. The estimated reduction of cochlear compression was significantly correlated with the increase in the F0DL ratio, while no correlation was found with filter bandwidth. The effects of degraded frequency selectivity and loss of compression were considered in a simplified peripheral model as potential factors in envelope enhancement. The model revealed that reducing cochlear compression significantly enhanced the envelope of an unresolved SP complex tone, while not affecting the envelope of a RP complex tone. This envelope enhancement in the SP condition was significantly correlated with the increased Pitch-Discrimination performance for the SP relative to the RP condition in the HI listeners.
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Pitch Discrimination in musicians and non musicians effects of harmonic resolvability and processing effort
Jaro-journal of The Association for Research in Otolaryngology, 2016Co-Authors: Federica Bianchi, Sebastien Santurette, Dorothea Wendt, Torsten DauAbstract:Musicians typically show enhanced Pitch Discrimination abilities compared to non-musicians. The present study investigated this perceptual enhancement behaviorally and objectively for resolved and unresolved complex tones to clarify whether the enhanced performance in musicians can be ascribed to increased peripheral frequency selectivity and/or to a different processing effort in performing the task. In a first experiment, Pitch Discrimination thresholds were obtained for harmonic complex tones with fundamental frequencies (F0s) between 100 and 500 Hz, filtered in either a low- or a high-frequency region, leading to variations in the resolvability of audible harmonics. The results showed that Pitch Discrimination performance in musicians was enhanced for resolved and unresolved complexes to a similar extent. Additionally, the harmonics became resolved at a similar F0 in musicians and non-musicians, suggesting similar peripheral frequency selectivity in the two groups of listeners. In a follow-up experiment, listeners’ pupil dilations were measured as an indicator of the required effort in performing the same Pitch Discrimination task for conditions of varying resolvability and task difficulty. Pupillometry responses indicated a lower processing effort in the musicians versus the non-musicians, although the processing demand imposed by the Pitch Discrimination task was individually adjusted according to the behavioral thresholds. Overall, these findings indicate that the enhanced Pitch Discrimination abilities in musicians are unlikely to be related to higher peripheral frequency selectivity and may suggest an enhanced Pitch representation at more central stages of the auditory system in musically trained listeners.
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effects of cochlear compression and frequency selectivity on Pitch Discrimination of complex tones with unresolved harmonics
Proceedings of the International Symposium on Auditory and Audiological Research, 2015Co-Authors: Federica Bianchi, Sebastien Santurette, Michal Fereczkowski, Johannes Zaar, Torsten DauAbstract:Physiological studies have shown that noise-induced sensorineural hearing loss (SNHL) enhances the amplitude of envelope coding in auditory-nerve fibers. As Pitch coding of unresolved complex tones is assumed to rely on temporal envelope coding mechanisms, this study investigated Pitch-Discrimination performance in listeners with SNHL. Pitch-Discrimination thresholds were obtained in 14 normal-hearing (NH) and 10 hearing-impaired (HI) listeners for sine-phase (SP) and random-phase (RP) unresolved complex tones. The HI listeners performed, on average, similarly as the NH listeners in the SP condition and worse than NH listeners in the RP condition. Cochlear compression and auditory filter bandwidths were estimated in the same listeners. A significant correlation was found between the reduction of cochlear compression and the difference between RP and SP Pitch-Discrimination thresholds. The effects of degraded frequency selectivity and loss of compression were considered in a model as potential factors in envelope enhancement. The model revealed that a broadening of the auditory filters led to an increase of the modulation depth in the SP condition, while it did not have any effect for the RP condition. Overall, these findings suggest that both reduced cochlear compression and auditory filter broadening alter the envelope representation of unresolved complex tones, leading to changes in Pitch-Discrimination performance.
Isabelle Peretz - One of the best experts on this subject based on the ideXlab platform.
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ability to process musical Pitch is unrelated to the memory advantage for vocal music
Brain and Cognition, 2019Co-Authors: Michael W Weiss, Isabelle PeretzAbstract:Listeners remember vocal melodies better than instrumental melodies, but the origins of the effect are unclear. One explanation for the 'voice advantage' is that general perceptual mechanisms enhance processing of conspecific signals. An alternative possibility is that the voice, by virtue of its expressiveness in Pitch, simply provides more musical information to the listener. Individuals with congenital amusia provide a unique opportunity to disentangle the effects of conspecific status and vocal expressiveness because they cannot readily process subtleties in musical Pitch. Forty-one participants whose musical Pitch Discrimination ability ranged from congenitally amusic to typical were tested. Participants heard vocal and instrumental melodies during an exposure phase, and heard the same melodies intermixed with timbre-matched foils in a recognition phase. Memory was better for vocal than instrumental melodies, but the magnitude of the advantage was unrelated to musical Pitch Discrimination or memory overall. The voice enhances melodic memory regardless of music perception ability, ruling out the role of Pitch expressiveness in the voice advantage. More importantly, listeners across a wide range of musical ability can benefit from the privileged status of the voice.
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activation in the right inferior parietal lobule reflects the representation of musical structure beyond simple Pitch Discrimination
PLOS ONE, 2016Co-Authors: Isabelle Royal, Dominique T Vuvan, Benjamin Rich Zendel, Nicolas Robitaille, Marc Schonwiesner, Isabelle PeretzAbstract:Pitch Discrimination tasks typically engage the superior temporal gyrus and the right inferior frontal gyrus. It is currently unclear whether these regions are equally involved in the processing of incongruous notes in melodies, which requires the representation of musical structure (tonality) in addition to Pitch Discrimination. To this aim, 14 participants completed two tasks while undergoing functional magnetic resonance imaging, one in which they had to identify a Pitch change in a series of non-melodic repeating tones and a second in which they had to identify an incongruous note in a tonal melody. In both tasks, the deviants activated the right superior temporal gyrus. A contrast between deviants in the melodic task and deviants in the non-melodic task (melodic > non-melodic) revealed additional activity in the right inferior parietal lobule. Activation in the inferior parietal lobule likely represents processes related to the maintenance of tonal Pitch structure in working memory during Pitch Discrimination.
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Pitch Discrimination without awareness in congenital amusia evidence from event related potentials
Brain and Cognition, 2013Co-Authors: Patricia Moreau, Pierre Jolicœur, Isabelle PeretzAbstract:Abstract Congenital amusia is a lifelong disorder characterized by a difficulty in perceiving and producing music despite normal intelligence and hearing. Behavioral data have indicated that it originates from a deficit in fine-grained Pitch Discrimination, and is expressed by the absence of a P3b event-related brain response for Pitch differences smaller than a semitone and a bigger N2b–P3b brain response for large Pitch differences as compared to controls. However, it is still unclear why the amusic brain overreacts to large Pitch changes. Furthermore, another electrophysiological study indicates that the amusic brain can respond to changes in melodies as small as a quarter-tone, without awareness, by exhibiting a normal mismatch negativity (MMN) brain response. Here, we re-examine the event-related N2b–P3b components with the aim to clarify the cause of the larger amplitude observed by Peretz, Brattico, and Tervaniemi (2005) , by experimentally matching the number of deviants presented to the controls according to the number of deviants detected by amusics. We also re-examine the MMN component as well as the N1 in an acoustical context to investigate further the Pitch Discrimination deficit underlying congenital amusia. In two separate conditions, namely ignore and attend, we measured the MMN, the N1, the N2b and the P3b to tones that deviated by an eight of a tone (25 cents) or whole tone (200 cents) from a repeated standard tone. The results show a normal MMN, a seemingly normal N1, a normal P3b for the 200 cents Pitch deviance, and no P3b for the small 25 cents Pitch differences in amusics. These results indicate that the amusic brain responds to small Pitch differences at a pre-attentive level of perception, but is unable to detect consciously those same Pitch deviances at a later attentive level. The results are consistent with previous MRI and fMRI studies indicating that the auditory cortex of amusic individuals is functioning normally.
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tone language fluency impairs Pitch Discrimination
Frontiers in Psychology, 2011Co-Authors: Isabelle Peretz, Sebastien Nguyen, Stephanie CummingsAbstract:Here we present evidence that native speakers of a tone language, in which Pitch contributes to word meaning, are impaired in the Discrimination of falling Pitches in tone sequences, as compared to speakers of a non-tone language. Both groups were presented with monotonic and isochronous sequences of five tones (i.e., constant Pitch and intertone interval). They were required to detect when the fourth tone was displaced in Pitch or time. While speakers of a tone language performed more poorly in the detection of downward Pitch changes, they did not differ from non-tone language speakers in their perception of upward Pitch changes or in their perception of subtle time changes. Moreover, this impairment cannot be attributed to low musical aptitude since the impairment remains unchanged when individual differences in musical Pitch-based processing is taken into account. Thus, the impairment appears highly specific and may reflect the influence of statistical regularities of tone languages.
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congenital amusia a disorder of fine grained Pitch Discrimination
Neuron, 2002Co-Authors: Isabelle Peretz, Robert J Zatorre, Julie Ayotte, Jacques Mehler, Pierre Ahad, Virginia B Penhune, Benoit JutrasAbstract:We report the first documented case of congenital amusia. This disorder refers to a musical disability that cannot be explained by prior brain lesion, hearing loss, cognitive deficits, socioaffective disturbance, or lack of environmental stimulation. This musical impairment is diagnosed in a middle-aged woman, hereafter referred to as Monica, who lacks most basic musical abilities, including melodic Discrimination and recognition, despite normal audiometry and above-average intellectual, memory, and language skills. The results of psychophysical tests show that Monica has severe difficulties with detecting Pitch changes. The data suggest that music-processing difficulties may result from problems in fine-grained Discrimination of Pitch, much in the same way as many language-processing difficulties arise from deficiencies in auditory temporal resolution.
Federica Bianchi - One of the best experts on this subject based on the ideXlab platform.
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effect of musical training on Pitch Discrimination performance in older normal hearing and hearing impaired listeners
Proceedings of the International Symposium on Auditory and Audiological Research, 2017Co-Authors: Federica Bianchi, Torsten Dau, Sebastien SanturetteAbstract:Hearing-impaired (HI) listeners, as well as elderly listeners, typically have a reduced ability to discriminate the fundamental frequency (F0) of complex tones compared to young normal-hearing (NH) listeners. Several studies have shown that musical training, on the other hand, leads to improved F0-Discrimination performance for NH listeners. It is unclear whether a comparable effect of musical training occurs for listeners whose sensory encoding of F0 is degraded. To address this question, F0 Discrimination was investigated for three groups of listeners (14 young NH, 9 older NH and 10 HI listeners), each including musicians and non-musicians, using complex tones that differed in harmonic content. Musical training significantly improved F0 Discrimination for all groups of listeners, especially for complex tones containing low-numbered harmonics. In a second experiment, the sensitivity to temporal fine structure cues (TFS) was estimated in the same listeners. Although TFS cues were degraded for the two older groups of listeners, musicians showed better performance than non-musicians. Additionally, a significant correlation was obtained between F0-Discrimination performance and sensitivity to TFS cues for complex tones with low and intermediate harmonic numbers. These findings suggest that musical training may enhance both sensory encoding of TFS cues and F0 Discrimination in young and older listeners with or without hearing loss.
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subcortical and cortical correlates of Pitch Discrimination evidence for two levels of neuroplasticity in musicians
NeuroImage, 2017Co-Authors: Federica Bianchi, Jens Hjortkjaer, Sebastien Santurette, Robert J Zatorre, Hartwig R Siebner, Torsten DauAbstract:Musicians are highly trained to discriminate fine Pitch changes but the neural bases of this ability are poorly understood. It is unclear whether such training-dependent differences in Pitch processing arise already in the subcortical auditory system or are linked to more central stages. To address this question, we combined psychoacoustic testing with functional MRI to measure cortical and subcortical responses in musicians and non-musicians during a Pitch-Discrimination task. First, we estimated behavioral Pitch-Discrimination thresholds for complex tones with harmonic components that were either resolved or unresolved in the auditory system. Musicians outperformed non-musicians, showing lower Pitch-Discrimination thresholds in both conditions. The same participants underwent task-related functional MRI, while they performed a similar Pitch-Discrimination task. To account for the between-group differences in Pitch-Discrimination, task difficulty was adjusted to each individual's Pitch-Discrimination ability. Relative to non-musicians, musicians showed increased neural responses to complex tones with either resolved or unresolved harmonics especially in right-hemispheric areas, comprising the right superior temporal gyrus, Heschl's gyrus, insular cortex, inferior frontal gyrus, and in the inferior colliculus. Both subcortical and cortical neural responses predicted the individual Pitch-Discrimination performance. However, functional activity in the inferior colliculus correlated with differences in Pitch Discrimination across all participants, but not within the musicians group alone. Only neural activity in the right auditory cortex scaled with the fine Pitch-Discrimination thresholds within the musicians. These findings suggest two levels of neuroplasticity in musicians, whereby training-dependent changes in Pitch processing arise at the collicular level and are preserved and further enhanced in the right auditory cortex.
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complex tone Pitch Discrimination in listeners with sensorineural hearing loss
Trends in hearing, 2016Co-Authors: Federica Bianchi, Sebastien Santurette, Michal Fereczkowski, Johannes Zaar, Torsten DauAbstract:Physiological studies have shown that noise-induced sensorineural hearing loss (SNHL) enhances the amplitude of envelope coding in auditory-nerve fibers. As Pitch coding of unresolved complex tones is assumed to rely on temporal envelope coding mechanisms, this study investigated Pitch-Discrimination performance in listeners with SNHL. Pitch-Discrimination thresholds were obtained for 14 normal-hearing (NH) and 10 hearing-impaired (HI) listeners for sine-phase (SP) and random-phase (RP) complex tones. When all harmonics were unresolved, the HI listeners performed, on average, worse than NH listeners in the RP condition but similarly to NH listeners in the SP condition. The increase in Pitch-Discrimination performance for the SP relative to the RP condition (F0DL ratio) was significantly larger in the HI as compared with the NH listeners. Cochlear compression and auditory-filter bandwidths were estimated in the same listeners. The estimated reduction of cochlear compression was significantly correlated with the increase in the F0DL ratio, while no correlation was found with filter bandwidth. The effects of degraded frequency selectivity and loss of compression were considered in a simplified peripheral model as potential factors in envelope enhancement. The model revealed that reducing cochlear compression significantly enhanced the envelope of an unresolved SP complex tone, while not affecting the envelope of a RP complex tone. This envelope enhancement in the SP condition was significantly correlated with the increased Pitch-Discrimination performance for the SP relative to the RP condition in the HI listeners.
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Pitch Discrimination in musicians and non musicians effects of harmonic resolvability and processing effort
Jaro-journal of The Association for Research in Otolaryngology, 2016Co-Authors: Federica Bianchi, Sebastien Santurette, Dorothea Wendt, Torsten DauAbstract:Musicians typically show enhanced Pitch Discrimination abilities compared to non-musicians. The present study investigated this perceptual enhancement behaviorally and objectively for resolved and unresolved complex tones to clarify whether the enhanced performance in musicians can be ascribed to increased peripheral frequency selectivity and/or to a different processing effort in performing the task. In a first experiment, Pitch Discrimination thresholds were obtained for harmonic complex tones with fundamental frequencies (F0s) between 100 and 500 Hz, filtered in either a low- or a high-frequency region, leading to variations in the resolvability of audible harmonics. The results showed that Pitch Discrimination performance in musicians was enhanced for resolved and unresolved complexes to a similar extent. Additionally, the harmonics became resolved at a similar F0 in musicians and non-musicians, suggesting similar peripheral frequency selectivity in the two groups of listeners. In a follow-up experiment, listeners’ pupil dilations were measured as an indicator of the required effort in performing the same Pitch Discrimination task for conditions of varying resolvability and task difficulty. Pupillometry responses indicated a lower processing effort in the musicians versus the non-musicians, although the processing demand imposed by the Pitch Discrimination task was individually adjusted according to the behavioral thresholds. Overall, these findings indicate that the enhanced Pitch Discrimination abilities in musicians are unlikely to be related to higher peripheral frequency selectivity and may suggest an enhanced Pitch representation at more central stages of the auditory system in musically trained listeners.
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effects of cochlear compression and frequency selectivity on Pitch Discrimination of complex tones with unresolved harmonics
Proceedings of the International Symposium on Auditory and Audiological Research, 2015Co-Authors: Federica Bianchi, Sebastien Santurette, Michal Fereczkowski, Johannes Zaar, Torsten DauAbstract:Physiological studies have shown that noise-induced sensorineural hearing loss (SNHL) enhances the amplitude of envelope coding in auditory-nerve fibers. As Pitch coding of unresolved complex tones is assumed to rely on temporal envelope coding mechanisms, this study investigated Pitch-Discrimination performance in listeners with SNHL. Pitch-Discrimination thresholds were obtained in 14 normal-hearing (NH) and 10 hearing-impaired (HI) listeners for sine-phase (SP) and random-phase (RP) unresolved complex tones. The HI listeners performed, on average, similarly as the NH listeners in the SP condition and worse than NH listeners in the RP condition. Cochlear compression and auditory filter bandwidths were estimated in the same listeners. A significant correlation was found between the reduction of cochlear compression and the difference between RP and SP Pitch-Discrimination thresholds. The effects of degraded frequency selectivity and loss of compression were considered in a model as potential factors in envelope enhancement. The model revealed that a broadening of the auditory filters led to an increase of the modulation depth in the SP condition, while it did not have any effect for the RP condition. Overall, these findings suggest that both reduced cochlear compression and auditory filter broadening alter the envelope representation of unresolved complex tones, leading to changes in Pitch-Discrimination performance.
Andreas Bahmer - One of the best experts on this subject based on the ideXlab platform.
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rate Pitch Discrimination in cochlear implant users with the use of double pulses and different interpulse intervals
Cochlear Implants International, 2019Co-Authors: Sabrina H Pieper, Andreas BahmerAbstract:The rate Pitch Discrimination ability of cochlear implant (CI) users is poor compared to normal-hearing (NH) listeners. At low pulse rates, the just noticeable difference (JND) is on average 20% of...
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psychometric function of jittered rate Pitch Discrimination
Hearing Research, 2014Co-Authors: Andreas Bahmer, Uwe BaumannAbstract:The impact of jitter on rate Pitch Discrimination (JRPD) is still a matter of debate. Previous studies have used adaptive procedures to assess Pitch Discrimination abilities of jittered rate pulses (Dobie and Dillier, 1985; Chen et al., 2005) or have used jitter detection thresholds (Fearn, 2001). Previous studies were conducted in a relatively small number of subjects using either a single-electrode cochlear implant (Dobie and Dillier, 1985, n ¼ 2) or the Nucleus multi-channel devices (Fearn, 2001, n ¼ 3; Chen et al., 2005, n ¼ 5). The successful application of an adaptive procedure requires a monotone psychometric function to achieve asymptotic results. The underlying psychometric function of rate jitter has not been investigated so far. In order to close this knowledge gap, the present study determines psychometric functions by measuring of JRPD with a fixed stimulus paradigm. A rather large range of temporal, Gaussian distributed jitter standard deviation 0, 1, 2, 3, 4 ms was applied to electrical pulse patterns. Since the shape of the underlying probability density function (PDF) may also effect JRPD, a uniform PDF was alternatively applied. 7 CI users (8 ears, high-level performers with open-speech perception, MED-EL Pulsar/Sonata devices, Innsbruck, Austria) served as subjects for the experiment. JRPD was assessed with a two-stage forced choice procedure. Gross results showed decreasing JRPD with increasing amounts of jitter independent of the applied jitter distribution. In conclusion, pulse rate jitter affects JRPD and therefore should be considered in current coding strategies.