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
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.
The roles of spectral cues and auditory plasticity in auditory localisation, speech segregation and speech intelligibility. Our recent work shows that high frequency energy in speech is important for the localisation of speech and may also aid in improving speech intelligibility in noisy environments. The work proposed here will systematically explore this somewhat surprising new finding and the results will be incorporated into a predictive model of speech intelligibility under spatial listenin ....The roles of spectral cues and auditory plasticity in auditory localisation, speech segregation and speech intelligibility. Our recent work shows that high frequency energy in speech is important for the localisation of speech and may also aid in improving speech intelligibility in noisy environments. The work proposed here will systematically explore this somewhat surprising new finding and the results will be incorporated into a predictive model of speech intelligibility under spatial listening conditions. This work includes a systematic study of auditory functional plasticity to changes in the spatial cues. Taken together, the outcomes of this work will unlock a range of new approaches to enhancing spatial hearing in multi-channel communication devices and spatial hearing aids.Read moreRead less
Acoustic, spatial and informational cues used to solve the cocktail party problem. Speech is the principal mode of human communication and yet we understand little about how we are able to concentrate on one talker against a noisy background. Significant improvements in supporting listening by the hearing impaired, in teleconferencing systems and computer speech interfaces are dependent on a more advanced understanding of how we solve this cocktail party problem. This research explores the acous ....Acoustic, spatial and informational cues used to solve the cocktail party problem. Speech is the principal mode of human communication and yet we understand little about how we are able to concentrate on one talker against a noisy background. Significant improvements in supporting listening by the hearing impaired, in teleconferencing systems and computer speech interfaces are dependent on a more advanced understanding of how we solve this cocktail party problem. This research explores the acoustic, spatial and informational cues used by the healthy auditory system to achieve this remarkable feat of signal processing. There is significant potential for commercialization of the IP that will arise from this research.Read moreRead less
Physiological significance of transient receptor potential (TRPC3) ion channels in the cochlea. The project seeks to discover the function of transient receptor potential (TRPC3) ion channels in the cochlea. Recent studies have suggested that these proteins, which are expressed by the sensory and neural cells, are key elements regulating sound transduction and neurotransmission. The new knowledge about the physiological processes underlying hearing that this work will provide, will significantl ....Physiological significance of transient receptor potential (TRPC3) ion channels in the cochlea. The project seeks to discover the function of transient receptor potential (TRPC3) ion channels in the cochlea. Recent studies have suggested that these proteins, which are expressed by the sensory and neural cells, are key elements regulating sound transduction and neurotransmission. The new knowledge about the physiological processes underlying hearing that this work will provide, will significantly benefit national and international translational research that seeks to develop systems for controlling the sensitivity of our senses, developing biosensors, interacting with neural networks and developing neural prostheses. International collaborators in this project have enabled development of new models, technology and research training opportunities.Read moreRead less
Suction pipette measurements of mammalian rod photoreceptor recovery following intense bleaching exposures. The aim of this project is to discover the events and processes that prevent retinal photoreceptors from recovering instantaneously following the cessation of exposure to extremely bright illumination. Recordings will be made from single rod photoreceptors cells isolated from the mammalian retina. The work will uncover the relative roles of the 'photoproducts' created when rhodopsin abso ....Suction pipette measurements of mammalian rod photoreceptor recovery following intense bleaching exposures. The aim of this project is to discover the events and processes that prevent retinal photoreceptors from recovering instantaneously following the cessation of exposure to extremely bright illumination. Recordings will be made from single rod photoreceptors cells isolated from the mammalian retina. The work will uncover the relative roles of the 'photoproducts' created when rhodopsin absorbs light: e.g. intermediates such as metarhodopsin and opsin. The molecular knowledge obtained will help us to understand why it is that the visual system recovers so slowly after the eye has experienced very intense light.Read moreRead less
The effect of multisensory and sensory-motor training on auditory accommodation. Learning to use a hearing aid or cochlear implant requires the brain to make adaptive changes to the new type of sensory information provided to the ears. This project examines what drives this accommodation and how we may accelerate the process and maximise its benefits by training so that listeners are able to make better use of these devices.
The first stage of vision: transduction and adaptation in retinal photoreceptors. The project aims to provide a detailed understanding of the molecular steps involved in the first stage of vision - the conversion of light into a neural signal in the rod and cone photoreceptors of the retina. The significance of this is that it will explain the initial events that enable us to see, and will help explain the deficits that occur when the process fails. The outcome will be a comprehensive understand ....The first stage of vision: transduction and adaptation in retinal photoreceptors. The project aims to provide a detailed understanding of the molecular steps involved in the first stage of vision - the conversion of light into a neural signal in the rod and cone photoreceptors of the retina. The significance of this is that it will explain the initial events that enable us to see, and will help explain the deficits that occur when the process fails. The outcome will be a comprehensive understanding of how our photoreceptors respond with extreme sensitivity, yet great rapidity, and over an enormous range of light intensities, thus endowing us with our remarkable sense of vision.Read moreRead less
A contractile cochlear frame - a possible new mechanism of sound adaptation. It is generally accepted that the rigid frame that harbours sensory structures in the hearing organs of modern higher vertebrates has only a passive supporting role. We have discovered a contractile component in the cartilaginous cochlear frame of the lizard Teratoscincus scincus and demonstrated that the tonus of the contractile tissue can be regulated. We hypothesize a new, previously unknown mechanism of slow mechani ....A contractile cochlear frame - a possible new mechanism of sound adaptation. It is generally accepted that the rigid frame that harbours sensory structures in the hearing organs of modern higher vertebrates has only a passive supporting role. We have discovered a contractile component in the cartilaginous cochlear frame of the lizard Teratoscincus scincus and demonstrated that the tonus of the contractile tissue can be regulated. We hypothesize a new, previously unknown mechanism of slow mechanical adaptation in the vertebrate hearing organ. The aim of the proposed project is to examine this hypothesis in more detail.
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Functional imaging of colour pathways in the living eye. In order to repair or regenerate a diseased eye, we require knowledge of the normal pattern or nerve cell connections, and knowing how biology solves the problem of colour vision can be used to improve the design of artificial vision systems. The adaptive optics machine we will build in this project can be used to image nerve cells, fine blood vessels, and nerve fibre bundles in the normal and diseased eye. This will improve Australia's re ....Functional imaging of colour pathways in the living eye. In order to repair or regenerate a diseased eye, we require knowledge of the normal pattern or nerve cell connections, and knowing how biology solves the problem of colour vision can be used to improve the design of artificial vision systems. The adaptive optics machine we will build in this project can be used to image nerve cells, fine blood vessels, and nerve fibre bundles in the normal and diseased eye. This will improve Australia's research and development capacity in this new area of medical diagnostics. Our machine will be made available to other Australian laboratories and will improve the national capacity for making further scientific discoveries about how the visual system works.Read moreRead less