Hearing Regeneration and Protection

Research Overview

Hearing loss can occur as a result of inner ear pathologies, trauma, excessive noise, pharmacological agents or ageing. Even after significant hearing loss, protecting the remaining residual hearing can provide significant functional and quality of life benefits for the sufferer. The Hearing Regeneration and Protection group is a team of surgeons, clinicians, scientists and engineers that work collaboratively to conduct both laboratory and clinical research focused on protecting and regenerating inner ear function after surgical, noise and other traumas.

A major focus of our work is developing therapies to protect residual hearing and minimise hearing loss and tissue response after cochlear implantation. This allows for hybrid hearing strategies (acoustic hearing combined with cochlear implants) to improve both music appreciation and speech perception in noisy environments. We are also interested in regenerating hearing following trauma from excessive noise - even mild trauma to the ear to can result in synaptopathy or loss of hair cell function. It was previously thought that hearing, once lost, was unable to be restored. However our group has recently demonstrated synapse regeneration may be possible and are currently developing clinical approaches to attempt to restore hearing.

Developing these therapies involves investigating pharmacological agents, optimising drug delivery to the inner ear, and detailed examination of inner ear pathologies and the biological response to trauma. Our collaboration with the Royal Victorian Eye and Ear Hospital enables us to rapidly translate our scientific findings into clinical practise through Clinical trials.


Dr Karina Needham, Senior Research Fellow

Dr Hayden Eastwood, Research Fellow

Dr Justin Tan, Research Fellow

Dr Christo Bester, Clinical Research Fellow

Amy Hampson, Research Assistant

Kate Brody, Research Assistant

Aaron Collins, Research Engineer

Katie Davis, Clinical Trial Coordinator

Dr Jessica Choong, PhD student


The Hearing Regeneration and Protection group collaborates with a number of groups and organisations around the world. A selection of our current collaborations include:

Professor Peter Throne, The University of Auckland
Professor Anthony Gummer, University of Tuebigen
Professor Jun Ho Lee, Seoul National University
Dr Nicholas Reynolds, ARC Training Centre for Biodevices, Swinburn University
Cochlear Ltd
Frequency Therapeutics


National Health and Medical Research Council

The Garnett Passe and Rodney Williams Memorial Foundation

Cochlear Ltd

Royal Victorian Eye and Ear Hospital

Research Outcomes

Lo J, Campbell L, Sale P, Chambers S, Hampson A, Eastwood H, O'Leary S. The
Role of Preoperative Steroids in Atraumatic Cochlear Implantation Surgery. Otol
Neurotol. 2017 Jul 11.

Chang MY, Rah YC, Choi JJ, Woo SW, Hwang YJ, Eastwood H, O'Leary SJ, Lee JH.
The Effect of Systemic Steroid on Hearing Preservation After Cochlear
Implantation via Round Window Approach: A Guinea Pig Model. Otol Neurotol. 2017

Lo J, Sale P, Wijewickrema S, Campbell L, Eastwood H, O'leary SJ. Defining the
Hook Region Anatomy of the Guinea Pig Cochlea for Modeling of Inner Ear Surgery.
Otol Neurotol. 2017 Jul;38(6):e179-e187

Rowe D, Chambers S, Hampson A, Eastwood H, O'Leary S. The Effect of Round
Window Sealants on Delayed Hearing Loss in a Guinea Pig Model of Cochlear
Implantation. Otol Neurotol. 2016 Sep;37(8):1024-31

Rah YC, Lee MY, Kim SH, Kim DH, Eastwood H, O'Leary SJ, Lee JH. Extended use
of systemic steroid is beneficial in preserving hearing in guinea pigs after
cochlear implant. Acta Otolaryngol. 2016 Dec;136(12):1213-1219.

Rowe D, Chambers S, Hampson A, Eastwood H, Campbell L, O'Leary S. Delayed low
frequency hearing loss caused by cochlear implantation interventions via the
round window but not cochleostomy. Hear Res. 2016 Mar;333:49-57.

Smeds H, Eastwood HT, Hampson AJ, Sale P, Campbell LJ, Arhatari BD, Mansour S,
O'Leary SJ. Endolymphatic hydrops is prevalent in the first weeks following
cochlear implantation. Hear Res. 2015 Sep;327:48-57.

Lee J, Ismail H, Lee JH, Kel G, O'Leary J, Hampson A, Eastwood H, O'Leary SJ.
Effect of both local and systemically administered dexamethasone on long-term
hearing and tissue response in a Guinea pig model of cochlear implantation.
Audiol Neurootol. 2013;18(6):392-405.

Kel GE, Tan J, Eastwood HT, Wongprasartsuk S, O'Leary SJ. Early cochlear
response and ICAM-1 expression to cochlear implantation. Otol Neurotol. 2013

King EB, Salt AN, Kel GE, Eastwood HT, O'Leary SJ. Gentamicin administration
on the stapes footplate causes greater hearing loss and vestibulotoxicity than
round window administration in guinea pigs. Hear Res. 2013 Oct;304:159-66.

O'Leary SJ, Monksfield P, Kel G, Connolly T, Souter MA, Chang A, Marovic P,
O'Leary JS, Richardson R, Eastwood H. Relations between cochlear histopathology
and hearing loss in experimental cochlear implantation. Hear Res. 2013

Souter M, Eastwood H, Marovic P, Kel G, Wongprasartsuk S, Ryan AF, O'Leary
SJ. Systemic immunity influences hearing preservation in cochlear implantation.
Otol Neurotol. 2012 Jun;33(4):532-8.

King EB, Salt AN, Eastwood HT, O'Leary SJ. Direct entry of gadolinium into
the vestibule following intratympanic applications in Guinea pigs and the
influence of cochlear implantation. J Assoc Res Otolaryngol. 2011

Enticott JC, Eastwood HT, Briggs RJ, Dowell RC, O'Leary SJ.
Methylprednisolone applied directly to the round window reduces dizziness after
cochlear implantation: a randomized clinical trial. Audiol Neurootol.

Connolly TM, Eastwood H, Kel G, Lisnichuk H, Richardson R, O'Leary S.
Pre-operative intravenous dexamethasone prevents auditory threshold shift in a
guinea pig model of cochlear implantation. Audiol Neurootol. 2011;16(3):137-44.

Eastwood H, Chang A, Kel G, Sly D, Richardson R, O'Leary SJ. Round window
delivery of dexamethasone ameliorates local and remote hearing loss produced by
cochlear implantation into the second turn of the guinea pig cochlea. Hear Res.
2010 Jun 14;265(1-2):25-9.

Maini S, Lisnichuk H, Eastwood H, Pinder D, James D, Richardson RT, Chang A,
Connolly T, Sly D, Kel G, O'Leary SJ. Targeted therapy of the inner ear. Audiol Neurootol. 2009;14(6):402-10.

Eastwood H, Pinder D, James D, Chang A, Galloway S, Richardson R, O'Leary S.
Permanent and transient effects of locally delivered n-acetyl cysteine in a
guinea pig model of cochlear implantation. Hear Res. 2010 Jan;259(1-2):24-30.

Chang A, Eastwood H, Sly D, James D, Richardson R, O'Leary S. Factors
influencing the efficacy of round window dexamethasone protection of residual
hearing post-cochlear implant surgery. Hear Res. 2009 Sep;255(1-2):67-72.

James DP, Eastwood H, Richardson RT, O'Leary SJ. Effects of round window
dexamethasone on residual hearing in a Guinea pig model of cochlear implantation.
Audiol Neurootol. 2008;13(2):86-96.

Research Projects

For project inquiries, contact our research group head.

Faculty Research Themes


School Research Themes

Neuroscience & Psychiatry

Key Contact

For further information about this research, please contact William Gibson Chair of Otolaryngology Professor Stephen O'Leary

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