Jos J. Eggermont
- Published in print:
- 2015
- Published Online:
- May 2015
- ISBN:
- 9780198719090
- eISBN:
- 9780191802232
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198719090.001.0001
- Subject:
- Neuroscience, Behavioral Neuroscience, Development
Sound is dynamic and as such has temporal and spectral content. The auditory system extracts the spectral aspects and the temporal ones in parallel in the cochlea and auditory nerve. For frequencies ...
More
Sound is dynamic and as such has temporal and spectral content. The auditory system extracts the spectral aspects and the temporal ones in parallel in the cochlea and auditory nerve. For frequencies below about 1.5 kHz, the spectral and temporal representations of sound are potentially redundant and both represent the pitch of speech and music. Auditory temporal processing determines our understanding of speech, our appreciation of music, being able to localize a sound source, and to listen to a person in a noisy crowd. The underlying basic capabilities of the auditory system include precise representation of sound onsets and offsets, representing gap durations in sound, and being able to code fast amplitude- and frequency- modulations of sound. The co-occurrence of such onsets and modulations of sound determine auditory objects and allow separating those from other auditory streams. Problems with precise temporal representations of sound occur in auditory neuropathy and multiple sclerosis and lead to a mismatch between auditory sensitivity and speech discrimination. In dyslexia, specific language impairment and auditory processing disorders, similar problems occur early in life and set up additional cognitive speech processing problems. General neurological disorders such as autism, schizophrenia and epilepsy, display temporal processing deficits, generally though as a result of local and global neural synchrony problems. These synchrony problems are reflected in various cortical rhythm abnormalities and lead to cognitive dysfunctions. They also present auditory temporal processing problems, particularly in the amplitude modulation domain.Less
Sound is dynamic and as such has temporal and spectral content. The auditory system extracts the spectral aspects and the temporal ones in parallel in the cochlea and auditory nerve. For frequencies below about 1.5 kHz, the spectral and temporal representations of sound are potentially redundant and both represent the pitch of speech and music. Auditory temporal processing determines our understanding of speech, our appreciation of music, being able to localize a sound source, and to listen to a person in a noisy crowd. The underlying basic capabilities of the auditory system include precise representation of sound onsets and offsets, representing gap durations in sound, and being able to code fast amplitude- and frequency- modulations of sound. The co-occurrence of such onsets and modulations of sound determine auditory objects and allow separating those from other auditory streams. Problems with precise temporal representations of sound occur in auditory neuropathy and multiple sclerosis and lead to a mismatch between auditory sensitivity and speech discrimination. In dyslexia, specific language impairment and auditory processing disorders, similar problems occur early in life and set up additional cognitive speech processing problems. General neurological disorders such as autism, schizophrenia and epilepsy, display temporal processing deficits, generally though as a result of local and global neural synchrony problems. These synchrony problems are reflected in various cortical rhythm abnormalities and lead to cognitive dysfunctions. They also present auditory temporal processing problems, particularly in the amplitude modulation domain.
Jos Eggerrmont
- Published in print:
- 2015
- Published Online:
- May 2015
- ISBN:
- 9780198719090
- eISBN:
- 9780191802232
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198719090.003.0001
- Subject:
- Neuroscience, Behavioral Neuroscience, Development
Accurate representation of the dynamic aspects of sound in the auditory nervous system are crucial in understanding speech, enjoying music, being able to localize a sound source, and make it possible ...
More
Accurate representation of the dynamic aspects of sound in the auditory nervous system are crucial in understanding speech, enjoying music, being able to localize a sound source, and make it possible to communicate in noisy environments. Stationary sounds are represented in the auditory system in a way that onsets and offsets produce more activity than the parts in between. This is called perstimulatory adaptation of firing rate. The mechanisms underlying it also play a role in the masking effects of other sounds on the ones of interest, and determine our sensitivity to periodically time varying sounds. Stimulus-specific adaptation also may be largely determined by this mechanism. The first five chapters in the book describe the role of adaptation mechanisms from auditory nerve to auditory cortex. Chapter 6 describes a simple phenomenological model that links together perstimulatory adaptation and recovery therefrom with forward masking and temporal modulation transfer functions. Neural synchronization and its role in brain rhythms and perception are elucidated. Based on this, the role of temporal processing in periodicity pitch, sound localization, stream segregation and scene analysis are reviewed. Temporal processing ability of the nervous system is affected by maturation as well as aging, and on top of that by hearing loss. Less clear is the role of temporal processing deficits in dyslexia, specific language impairment and auditory processing disorders, potentially because of the confounding role of maturation and aging. Various neurological disorders such as auditory neuropathy, multiple sclerosis, schizophrenia, autism and epilepsy present itself with temporal processing deficits. These deficits are often multimodal in nature and this is reflected on in the final chapter.Less
Accurate representation of the dynamic aspects of sound in the auditory nervous system are crucial in understanding speech, enjoying music, being able to localize a sound source, and make it possible to communicate in noisy environments. Stationary sounds are represented in the auditory system in a way that onsets and offsets produce more activity than the parts in between. This is called perstimulatory adaptation of firing rate. The mechanisms underlying it also play a role in the masking effects of other sounds on the ones of interest, and determine our sensitivity to periodically time varying sounds. Stimulus-specific adaptation also may be largely determined by this mechanism. The first five chapters in the book describe the role of adaptation mechanisms from auditory nerve to auditory cortex. Chapter 6 describes a simple phenomenological model that links together perstimulatory adaptation and recovery therefrom with forward masking and temporal modulation transfer functions. Neural synchronization and its role in brain rhythms and perception are elucidated. Based on this, the role of temporal processing in periodicity pitch, sound localization, stream segregation and scene analysis are reviewed. Temporal processing ability of the nervous system is affected by maturation as well as aging, and on top of that by hearing loss. Less clear is the role of temporal processing deficits in dyslexia, specific language impairment and auditory processing disorders, potentially because of the confounding role of maturation and aging. Various neurological disorders such as auditory neuropathy, multiple sclerosis, schizophrenia, autism and epilepsy present itself with temporal processing deficits. These deficits are often multimodal in nature and this is reflected on in the final chapter.
