This project examines the types of computations used by brain cells to combine two types of sensory information, in a way that allow us to reach better decisions in everyday life. To address this general problem, we will perform experiments that explore the combination of signals from vision and hearing. The ability to combine sensory information is vital to our mental health, and this process is compromised in a range of psychological, psychiatric and neurological disorders.
Occupational Hearing Loss Induced By Solvents And Noise: Development Of New Strategies For Hearing Loss Prevention Programs In The Workplace
Funder
National Health and Medical Research Council
Funding Amount
$252,088.00
Summary
There are no guidelines on how to prevent and monitor the effects of solvents on hearing. There is an urgent need of an audiological test battery capable of detecting early signs of occupational solvent-induced hearing loss (OSIHL). It is the aim of this research to a) investigate the influence of solvent and noise exposure on the function of the auditory system, and b) determine the tests with the highest discriminatory power to detect early signs of OSIHL that can be used in the workplace.
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.
Intrinsic Hearing Protection Mechanisms: A Pathway To Prevention Of Noise-induced Hearing Loss
Funder
National Health and Medical Research Council
Funding Amount
$625,900.00
Summary
Noise-induced hearing loss (NIHL) is a significant contributor to the total burden of disease. We recently determined that when the ear is exposed to sustained noise, the cochlea is protected from damage by activation of a specific (P2X2) receptor, evident as reversible hearing adaptation. This study will determine the downstream signalling from this receptor. This will support assessment of vulnerability to NIHL and contribute to development of hearing therapeutics.
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.
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.
Studies Of The Effects Of Asymmetric Hearing Loss On The Brain
Funder
National Health and Medical Research Council
Funding Amount
$920,076.00
Summary
Hearing loss impairs the normal development and maintenance of auditory pathways. Irreversible pathologies persist when hearing is not restored in a timely manner. While cochlear implantation is the accepted treatment for profound sensorineural hearing loss, there is significant variability in outcomes. Some of this variability is linked to the degree of hearing asymmetry. Thus, we propose to study brain changes in the auditory system that accompany asymmetric hearing impairment.
Local Sleep In The Awake Brain: An Underlying Cause Of Neurobehavioural Deficits In Sleep Apnea?
Funder
National Health and Medical Research Council
Funding Amount
$582,330.00
Summary
Obstructive sleep apnea (OSA) is a common sleep disorder which significantly impacts daytime functioning leading to excessive sleepiness, and problems with attention and thinking. Currently, the causes for cognitive impairment in OSA (including attentional lapses and performance deficits) are poorly understood. In the awake state, groups of neurons can briefly go “offline” as they do in sleep. These periods of “local sleep” may explain impaired task performance in OSA.
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.
Bilateral Cochlear Implants: Restoring Binaural Processing By Experience And Training With Binaural Cues
Funder
National Health and Medical Research Council
Funding Amount
$968,030.00
Summary
Cochlear implantation in both ears is increasingly common and while there are benefits, performance falls short of expectations, likely due to the degradation of the long-term deaf brain’s sensitivity to small timing differences of sounds reaching each of the two ears. By confirming the hypothesis that experience with high-fidelity timing information will improve performance, this study will drive the technical innovations required to maximise the benefits and investment of bilateral implants.