Early Indicators Of Noise Injury: Are Decreased Auditory Processing Skills Evident In Noise-exposed Adults Prior To Diagnosis Of Hearing Loss?
Funder
National Health and Medical Research Council
Funding Amount
$367,605.00
Summary
Recent research indicates that noise-exposed individuals with similar hearing thresholds to non-noise exposed counterparts are more likely to have diminished temporal and spectral auditory processing abilities. This research aims to determine the relationship between noise exposure levels and auditory processing difficulties; the influence of musical training in ameliorating these difficulties; and a neurological model of causation, operation and possible remediation of these difficulties.
Cochlear Type II Neurons In Contralateral Suppression
Funder
National Health and Medical Research Council
Funding Amount
$459,434.00
Summary
Sound in one ear affects hearing in the other ear. This contralateral suppression is important for hearing attention and protection from noise damage. We will test the hypothesis that cochlear type II sensory neurons provide the sensory input for this process using models where neuronal development is altered, or the neurons are removed. The study addresses hearing disability in society, facilitating cochlear prosthesis development and the understanding of hearing loss.
Signals And Noise: A Study Of The Neurocognitive Mechanisms Underpinning Habituation To Noise In Normal And Damaged Hearing
Funder
National Health and Medical Research Council
Funding Amount
$408,938.00
Summary
McLachlan and Wilson recently published the first model of hearing that combines brain structure with function. This model postulates that recognition mechanisms initiate first, and then regulate the processing of other features. This project will investigate whether recognition mechanisms enable the auditory system to adapt to repetitive (background) noise by predicting and inhibiting responses to these sounds, and any changes in these mechanisms that may accompany hearing damage and tinnitus.
Auditory Processing Deficits In Specific Language Impairment And Specific Reading Disability:Their Effects And Treatment
Funder
National Health and Medical Research Council
Funding Amount
$314,250.00
Summary
One possible cause of specific language impairment (SLI) and specific reading disability (SRD; commonly known as dyslexia) is an inability to discriminate between sounds. Such an impairment could affect the ability to discriminate between simple speech sounds (phonemes) which are the basic building blocks for developing spoken language and reading skills. How many children with SLI or SRD have poor sound discrimination? What pattern of spoken language and reading impairments do these children ha ....One possible cause of specific language impairment (SLI) and specific reading disability (SRD; commonly known as dyslexia) is an inability to discriminate between sounds. Such an impairment could affect the ability to discriminate between simple speech sounds (phonemes) which are the basic building blocks for developing spoken language and reading skills. How many children with SLI or SRD have poor sound discrimination? What pattern of spoken language and reading impairments do these children have as a result of this impairment? Can poor sound discrimination be fixed? If it can, does it improve spoken language and reading impairments? And if it does, does it have an immediate effect or does it take some time to make a difference? These are some of the questions that will be addressed by this research. The answers will help us develop a training program that focuses specifically on improving the sound discrimination abilities of children who really need it. This will be a more efficient and inexpensive (if not free) than the Fast ForWord program that trains multiple non-verbal and verbal processing abilities regardless of whether a child has an impairment in all (or any) of these abilities and is therefore time consuming (approximately 80 hours) and expensive (approximately $AUD2000). The data will also help up better identify the spoken and written language profiles that characterise children who have sound discrimination deficits so we can better predict whether they would benefit from training programs such as Fast ForWord. And the data will tell use whether impaired sound discrimination can be used to predict whether infants might be at risk for later spoken language and reading problems.Read moreRead less
An Integrated Psychoacoustic And High-field FMRI Study Of Auditory Temporal Processsing Dysfunction In Schiophrenia.
Funder
National Health and Medical Research Council
Funding Amount
$306,000.00
Summary
This research seeks to improve our understanding of the causes of brain dysfunction in schizophrenia. This chronic and debilitating psychiatric disorder is usually accompanied by dramatic symptoms such as hallucinations, delusions, paranoia and disordered patterns of thinking. Based on our interpretation of evidence from a number of fields of schizophrenia research we suspect that the brain dysfunction in schizophrenia may not in the brain areas responsible for those dramatic symptoms but occurs ....This research seeks to improve our understanding of the causes of brain dysfunction in schizophrenia. This chronic and debilitating psychiatric disorder is usually accompanied by dramatic symptoms such as hallucinations, delusions, paranoia and disordered patterns of thinking. Based on our interpretation of evidence from a number of fields of schizophrenia research we suspect that the brain dysfunction in schizophrenia may not in the brain areas responsible for those dramatic symptoms but occurs initially in the very basic sensory regions of the brain. These regions can be thought of as providing the building blocks of our perceptions, that ultimately allow us to see, hear, smell and feel. Our previous research shows that people with schizophrenia have a very specific problem in the way that they perceive sounds. Using measures of brain activity, people with schizophrenia show consistent evidence that their brains do not process some of the timing information contained in sound. This is not the same as saying that people with schizophrenia are deaf, the deficits we see are much more subtle. It's a bit like the chaos theory analogy of a butterfly fluttering in Brazil and causing a typhoon in China. We think that very small alterations in brain activity in the initial stages of sensory processing can cascade through successively more complex stages of the brain, eventually creating the psychotic storm that becomes evident as the primary symptoms of schizophrenia. The brain regions we are interested in are located down at the base of the brain, in the brainstem, and it is only recently that the technology and methods of analysis we need to look at this activity have been developed. In this research we will be using functional magnetic resonance imaging and sophisticated hearing tests to examine whether these brain regions show the alterations we expect. If so, this will mean that the brain dysfunction in schizophrenia is quite different to what is currently believed.Read moreRead less
Development Of The Listening In Spatialized Noise - Tonal Test (or LiSN-T)
Funder
National Health and Medical Research Council
Funding Amount
$227,136.00
Summary
In this project a novel listening test software will be developed for diagnosing spatial processing disorder in children. These children often have difficulties in understanding teachers in classrooms, which can significantly impact their ability to learn. The developed software will be specifically designed for diagnosing 5-year old children, before they enter primary school, and in contrast to existing tests will be independent of their language background.
Abnormal Auditory System Function In Schizophrenia: An ERP And MEG Study Of Its Origin, Course And Generality.
Funder
National Health and Medical Research Council
Funding Amount
$250,770.00
Summary
In 1991, an Australian group found that schizophrenia patients have a reduced brain response to deviant sounds in a repeating pattern of identical sounds. Deviant sounds produce a brain electrical response known as mismatch negativity which is generated by the auditory cortex in the brain's temporal lobes and by adjacent areas in the frontal lobes. A smaller mismatch negativity in patients has since been replicated in laboratories in the US, Europe and Australia. The importance of this finding i ....In 1991, an Australian group found that schizophrenia patients have a reduced brain response to deviant sounds in a repeating pattern of identical sounds. Deviant sounds produce a brain electrical response known as mismatch negativity which is generated by the auditory cortex in the brain's temporal lobes and by adjacent areas in the frontal lobes. A smaller mismatch negativity in patients has since been replicated in laboratories in the US, Europe and Australia. The importance of this finding is that it had not been previously recognised that patients have low level auditory problems that could potentially have a profound impact on higher level functions. Finnish researchers have gone on to show in healthy individuals that mismatch negativity can reveal important features about how well the auditory system works, e.g., for the brain to respond to a deviant sound, it must have a memory of what happened in the past. Mismatch negativity provides a measure of the integrity of these memory functions. But it also provides an index of how well the auditory system discriminates different aspects of sound, pitch, loudness, and temporal features, such as duration. There are hints in our data and from US researchers that processing of the temporal features of sounds is particularly impaired in schizophrenia. We have also recently discovered that first-degree relatives of patients may have a similar deficit. The aim of this project is to use mismatch negativity to probe what is wrong with the auditory system in schizophrenia and those at risk (first degree relatives). Is it the areas of the brain primarily involved in sound perception (the temporal lobes) that are faulty or is the problem in the frontal lobes? Is it the case that processing of temporal features are particularly compromised and if so, is this a biological marker for schizophrenia. Answers to these questions will greatly enhance our understanding of the nature of the brain dysfunction in schizophrenia.Read moreRead less
Organization Of Descending Auditory Projections From Inferior Colliculus To Cochlear Nucleus
Funder
National Health and Medical Research Council
Funding Amount
$473,121.00
Summary
Sensory information gains awareness by ascending brain pathways to reach consciousness. Descending projections, however, have grown in importance because of implications for feedback management of ascending signals. Studies of these pathways will provide insight into auditory processing with respect to selective volume control, calibration adjustments between the two ears, and the extraction of signals from background noise. The data could lead to new strategies for treating hearing disorders.