Hearing Cooperative Research Center

Melbourne, Australia

Hearing Cooperative Research Center

Melbourne, Australia
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Souter M.A.,Christchurch Hospital | Briggs R.J.S.,University of Melbourne | Briggs R.J.S.,Hearing Cooperative Research Center | Wright C.G.,Southwestern Medical Center | Roland P.S.,Southwestern Medical Center
Otology and Neurotology | Year: 2011

Hypothesis: The goal of this human temporal bone study was to assess the safety and efficacy of round window insertion of the Cochlear Contour Advance electrode and identify any anatomic obstacles that may affect its insertion. Background: Minimizing intracochlear trauma during electrode insertion reduces the risk of losing residual hearing. The Contour Advance electrode is designed for insertion via an anteroinferior cochleostomy, in which drilling causes a degree of inner ear trauma. If consistently successful round window insertions are possible with this electrode, it would allow for better perimodiolar positioning in the basal turn and greater likelihood of hearing preservation. Methods: A total of 16 human temporal bone round window insertions with the Contour Advance electrode were performed at the University of Melbourne and Southwestern Medical Center, Dallas. Surgeons' observations, fluoroscopy, histology and anatomic dissections were analyzed. Results: Successful full insertions of the electrode with minimal resistance and good perimodiolar placement were achieved in less that 50% of cases in the Melbourne series and in two-thirds of cases in the Dallas series. A common finding by both centers was obstruction of electrode entry at the anteroinferior margin of the round window, which prevented optimal scala tympani positioning and often resulted in intracochlear trauma. Conclusion: The anteroinferior region of the round window bony margin influences the trajectory of insertion of the relatively large Contour Advance electrode as well as physically obstructing and distorting the array. A pure round window insertion is not predictable and reliable enough to be a recommended approach for this electrode. © 2010, Otology & Neurotology, Inc.

Carpinelli M.R.,Murdoch Childrens Research Institute | Carpinelli M.R.,Walter and Eliza Hall Institute of Medical Research | Carpinelli M.R.,Hearing Cooperative Research Center | Wise A.K.,Bionics Institute | And 13 more authors.
Cell Death and Disease | Year: 2012

In this paper we describe novel and specific roles for the apoptotic regulators Bcl2 and Bim in hearing and stapes development. Bcl2 is anti-apoptotic while Bim is pro-apoptotic. Characterization of the auditory systems of mice deficient for these molecules revealed that Bcl2 -/- mice suffered severe hearing loss. This was conductive in nature and did not affect sensory cells of the inner ear, with cochlear hair cells and neurons present and functional. Bcl2 -/- mice were found to have a malformed, often monocrural, porous stapes (the small stirrup-shaped bone of the middle ear), but a normally shaped malleus and incus. The deformed stapes was discontinuous with the incus and sometimes fused to the temporal bones. The defect was completely rescued in Bcl2 -/- Bim -/- mice and partially rescued in Bcl2 -/- Bim+/- mice, which displayed high-frequency hearing loss and thickening of the stapes anterior crus. The Bcl2 -/- defect arose in utero before or during the cartilage stage of stapes development. These results implicate Bcl2 and Bim in regulating survival of second pharyngeal arch or neural crest cells that give rise to the stapes during embryonic development. © 2012 Macmillan Publishers Limited.

Williams W.,National Acoustic Laboratories | Williams W.,Hearing Cooperative Research Center | Carter L.,National Acoustic Laboratories | Carter L.,Hearing Cooperative Research Center | And 2 more authors.
Noise and Health | Year: 2015

This paper reports on the examination of the relationship between self-reported historical noise exposure during leisure activities and audiological indicators: Measured hearing threshold levels (HTLs) and otoacoustic emissions (OAEs). The research was conducted by a cross-sectional survey of 1,432 individuals whose ages ranged from 11 years to 35 years. Methodology included a comprehensive audiometric assessment including otoscopy, pure tone audiometry (PTA) (air- and bone-conduction), OAEs, and tympanometry. A comprehensive questionnaire gathered information on demographics, hearing health status, and participation in work, nonwork, and leisure activities. Using the history of work, nonwork, and leisure noise exposure, a cumulative lifetime noise exposure was estimated. No correlation was found between cumulative lifetime noise exposure and audiometric PTA or OAE parameters. © 2015 Noise & Health | Published by Wolters Kluwer - Medknow.

Gilliver M.,Macquarie University | Gilliver M.,Hearing Cooperative Research Center | Beach E.F.,Macquarie University | Williams W.,Macquarie University | Williams W.,Hearing Cooperative Research Center
International Journal of Audiology | Year: 2015

Objective: To investigate factors influencing young people's motivation to reduce their leisure noise exposure, and protect their hearing health. Design: Questionnaires were conducted online to investigate young people's hearing health attitudes and behaviour. Items were developed using an integrated health promotion approach. The stage of change model was used to group participants in relation to their engagement with noise reduction behaviour. The health belief model was used to compare each group's perceptions of susceptibility and severity of hearing loss, as well as the benefits and barriers to noise reduction. Study sample: Results are presented for 1196 young Australians aged between 18 and 35 years. Results: Participants' engagement with noise reduction behaviour was used to assign them to stage of change groupings: Maintenance (11%), Action (28%), Contemplation (14%), or Pre-contemplation (43%). Each group's responses to health belief model items highlighted key differences across the different stages of engagement. Conclusions: Future hearing health promotion may benefit from tailoring intervention activities to best suit the stage of change of individuals. Different information may be useful at each stage to best support and motivate young people to look after their hearing health. © 2014 British Society of Audiology, International Society of Audiology, and Nordic Audiological Society.

Carter L.,Macquarie University | Williams W.,Macquarie University | Williams W.,Hearing Cooperative Research Center | Black D.,University of Sydney | Bundy A.,University of Sydney
Ear and Hearing | Year: 2014

The authors undertook a review of the literature, focussing on publications describing the following: (1) Pure tone threshold data for adolescents/young adults; (2) Measurements/estimates of noise exposure from leisure activities; and (3) The relationship between hearing threshold levels (HTLs) and leisure-noise exposure. There is a large volume of published materials relevant to these topics, and opinion among authors regarding the relationship between leisure-noise exposure and HTLs varies significantly. At one extreme is the view that the effects of leisure-noise are minimal. The opposing belief is that as a direct result of leisure-noise exposure, significant HTL shifts and possibly significant hearing disability are occurring in a large (and increasing) proportion of young people. It has been claimed that behaviors relating to leisure-noise are "as threatening to young people's health as more traditional risk behaviors" (, p. 55). This view has been reiterated by the popular media. This review revealed that while sufficient data confirm that some leisure pursuits provide potentially hazardous noise levels, the nature of the exposure-injury relationship for leisure-noise is yet to be determined. Specific information about the quality-of-life effects of threshold shift related to leisure-noise exposure is also lacking. The scope and limitations of a large sample of relevant publications and an overview of the methodological issues in this area of research are briefly presented. Considerations for future research are raised. © 2014 by Lippincott Williams & Wilkins.

Beach E.,National Acoustic Laboratories | Williams W.,National Acoustic Laboratories | Williams W.,Hearing Cooperative Research Center | Gilliver M.,National Acoustic Laboratories | Gilliver M.,Hearing Cooperative Research Center
20th International Congress on Acoustics 2010, ICA 2010 - Incorporating Proceedings of the 2010 Annual Conference of the Australian Acoustical Society | Year: 2010

Maximum acceptable noise exposure levels are well established for the workplace. For example, Australian occupational health and safety regulations mandate a maximum acceptable daily workplace noise exposure level (LAeq, 8h) of 85 dB (INCE: 1997). However, a person's day extends beyond the 8 hours spent at work, and thus noise exposure during non-working hours (leisure time) also contributes to a person's overall noise exposure. To investigate the levels of noise experienced during leisure activities, a long term study (Study 1) is under way. Measurements are being undertaken in 7 main categories: attendance at entertainment venues, attendance at sports venues, active recreation and sport, arts and cultural activities, travel, domestic activities, and other activities. In conjunction with these measurements of individual activities, a second study is also under way to measure individuals' noise exposure levels over an extended period. Participants wear personal noise dosimeters which measure their personal noise exposure levels over a 4- or 5-day period, including work days and weekend (leisure) days. Data collected thus far reveals that, while many leisure activities are below the acceptable noise levels and are thus 'safe', there are other leisure activities which, if engaged in regularly over a long period of time, have the potential to shift a person's noise exposure beyond acceptable limits and thus increase the risk of acquiring a hearing loss at a relatively early age.

Beach E.F.,Macquarie University | Gilliver M.,Macquarie University | Gilliver M.,Hearing Cooperative Research Center | Williams W.,Macquarie University | Williams W.,Hearing Cooperative Research Center
Applied Acoustics | Year: 2014

There have been several previous studies into daily noise exposure levels in modern urban communities, which typically report mean noise exposure levels (LAeq) for adults between 73 and 79 dB. In this study, rather than focus on group mean exposures across a wide age range, individual patterns of noise exposure over 4- and 5-day periods were examined in a group of 45 young adults aged 18-35 years. The main objective of the study was to determine the extent to which young adults exhibit a 'binge listening' pattern of noise exposure, i.e., high weekend leisure noise vs. low weekday work noise exposure. A secondary objective was to identify the types of activities that generate the highest noise exposures. The results showed that although most participants (60%) were exposed to low daily noise levels, 33% of participants exhibited a 'binge listening' exposure pattern characterized by one or two high-noise days, usually a Friday, Saturday or Sunday, preceded or followed by much quieter days. The most notable high-noise activities were playing an instrument solo or in a band; attending a nightclub; and attending a pop concert, each of which recorded average noise levels greater than 100 dB. Future research is needed to determine whether 'binge listening' is more or less harmful than the chronic exposure presupposed in traditional risk models, however, under the equal-energy principle, repeated 'binge' noise exposures from weekend visits to nightclubs, live music events and other high-noise events represent a significant risk to long-term hearing health. © 2013 Published by Elsevier Ltd. All rights reserved.

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