Extraction Of Key Features Of Natural Speech By Ventral Cochlear Nucleus Neurons
Funder
National Health and Medical Research Council
Funding Amount
$225,330.00
Summary
Little is known about how speech is processed and transformed by the central auditory pathway, and how the critical temporal and spectral features that identify a speech sound segment (a phoneme) are extracted. To date, most studies have approached this issue by using synthetic speech and examined the responses of the peripheral auditory nerve only. The aim of this study is to examine how important features of naturally-spoken speech are encoded by the cochlear nucleus (CN) - the first station i ....Little is known about how speech is processed and transformed by the central auditory pathway, and how the critical temporal and spectral features that identify a speech sound segment (a phoneme) are extracted. To date, most studies have approached this issue by using synthetic speech and examined the responses of the peripheral auditory nerve only. The aim of this study is to examine how important features of naturally-spoken speech are encoded by the cochlear nucleus (CN) - the first station in the auditory pathway located in the brainstem. The CN is a complex of different cell types that have the capacity to transmit, transform, and encode complex acoustic information in different ways. The proposed experiments involve recording the bioelectrical signal from single CN cells in anaesthetised rats while presenting naturally-spoken syllables, both in quiet and in the presence of noise. It is important to examine what happens to the neural responses in the latter condition, because all animals must cope with the problem of extracting important signals from background noise. While noise clearly interferes with the perception of another sound, the auditory system is in fact quite good at extracting signals in the presence of noise. This is well demonstrated by our ability to understand speech in the presence of quite high noise levels. This ability is severely degraded in the hearing impaired. Thus, one of the aims of this study is to examine the mechanisms and limits of the CN's ability to encode speech in a noisy background. A greater understanding of the mechanisms the nervous system uses to extract critical features of speech will not only build on our knowledge of auditory brainstem processes, but may also provide clues to improving processing strategies for cochlear implants.Read moreRead less
Improving Music Appreciation For People With Prosthetic Hearing Devices By Enhancing Auditory Stream Segregation
Funder
National Health and Medical Research Council
Funding Amount
$266,560.00
Summary
Music perception is one of the most often-cited problems for people with hearing aids or cochlear implants. Part of the problem is related to the reduced ability to hear different instruments or melodic lines separately. This ability is based on perceptual differences between auditory streams. Psychophysics experiments will be performed to understand the effect of different acoustic parameters on auditory streaming. An innovative approach to restore music appreciation will be tested on people wi ....Music perception is one of the most often-cited problems for people with hearing aids or cochlear implants. Part of the problem is related to the reduced ability to hear different instruments or melodic lines separately. This ability is based on perceptual differences between auditory streams. Psychophysics experiments will be performed to understand the effect of different acoustic parameters on auditory streaming. An innovative approach to restore music appreciation will be tested on people with impaired hearing.Read moreRead less
In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results wi ....In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results will improve our understanding of how we detect sounds and the impact of hearing pathologies on this process.Read moreRead less
The Contribution Of Dopamine To Regulation Of Orofacial, Limb And Trunk Control: System Or Function Specific Effects?
Funder
National Health and Medical Research Council
Funding Amount
$493,124.00
Summary
Treatment for Parkinson's disease, including dopamine replacement therapy and deep brain stimulation, fail to produce the same beneficial effects on all movement systems. Whereas limb function is the primary beneficiary of these treatments, other functions such as speech and postural control are less responsive. Critical to the research is the postulate that such differences may have arisen due to the fact that previous studies of dopamine and movement control have investigated distinct motor sy ....Treatment for Parkinson's disease, including dopamine replacement therapy and deep brain stimulation, fail to produce the same beneficial effects on all movement systems. Whereas limb function is the primary beneficiary of these treatments, other functions such as speech and postural control are less responsive. Critical to the research is the postulate that such differences may have arisen due to the fact that previous studies of dopamine and movement control have investigated distinct motor systems via the assessment of distinct movement constructs, making cross system comparisons an impossible task. The proposed research will assess the effect of Parkinson's disease, deep brain stimulation and dopamine on identical muscle functions within the orofacial, trunk and limb muscle systems. To this end, the results generated from this resarch have the potential to reconceptualise working models of brain-muscle relationships. Further the research will provide guidance for future studies that aim to eradicate trade-off effects (e.g. limb function improved but not speech) relating to symptom relief for people with Parkinson's disease.Read moreRead less