Medicine, Dentistry and Health SciencesDepartment of Otolaryngology

As indicated below, some projects are conducted in collaboration with the Bionic Ear Institute  or the HEARing CRC 

Use and development of a cochlear stimulation model

Supervisors: Dr Carrie Newbold, Ms Dimitra Stathopoulos, A/Prof Bob Cowan

Project suitability: Advanced Medical Science, Honours, PhD, Masters of Engineering Project

The electrode-neural interface of the cochlear implant presents an obvious bottleneck for information transfer, and a fertile ground for research. The cochlear implant uses only 22 electrodes to stimulate up to 50,000 spiral ganglion neurons, replacing the work of tens of thousands of hair cells. There are many potential methods of improving the safety, efficiency and specificity of cochlear implant stimulation; such as, more electrodes, electrodes closer to the neural elements, smaller electrodes as well as work on the electrical pulses delivered.

This project will extend on the current in vitro model of the electrode-tissue interface by improving the physical structure of the model and including a measurement of current path. The student would be part of an existing project group, and as such, the student's component may include model development, validation or use. This project is linked with Cochlear Ltd, and as such, the successful applicant may be required to present their results in written and/or oral reports to the larger research team.

The applicant will ideally have a keen interest in applied research on biomedical engineering, electrochemistry, electrical engineering and/or cell biology.

Techniques that you may learn:
* Use of oscilloscope & other engineering equipment
* Electrical engineering concepts
* Sterile technique
* Cell biology techniques
* Minor surgery
* Fluorescent and light microscopy
* Imaging and analysis
* Statistical analysis of results

Evaluation of alternative fabrication methods for electrode array for Cochlear implants

Supervisor: Dr Silvana Mergen

The cochlear electrode array is essential for delivering electrical stimulation to the neurons. The electrode design will affect the charge delivery, the current path and the number of stimulated neurons. The aim of this project is to evaluate somewhat recent technologies that have not been previously used in the fabrication of a Cochlear electrode array and their application potential for the development of novel electrode array.

This project is suitable for students of material science, electronic engineering or physics with interest in applied biomedical research. It is an ongoing project and the specific area for student's project is greatly dependent on the student's skills, interests and the scale of the project.

It is likely that this project would involve some independent work in the clean room facilities and would require lots of material and device characterization.

Techniques that you may learn:

* Photolithography or other microfabrication techniques
* Working practice in the clean room environment
* Optical and electron microscopy
* Electrochemical characterisation
* Principals of in vitro testing and electrical stimulation 

Developing surgical techniques to deliver stem cells to the deaf cochlea

Supervisor: Dr Bryony Nayagam

Project suitability: Advanced Medical Science, Honours, Masters, PhD

The broad aim of our research is to determine whether stem cells can be used to replace auditory neurons in the cochlea. The auditory neurons die as a result of hearing loss, and are essential for cochlear implant function. This project will build upon our previous studies, which were aimed at delivering stem cells into the deaf cochlea whilst minimising damage to this delicate structure. The ultimate goal of the project is to develop a surgical model to access the auditory nerve, such that stem cell therapy can be combined with a cochlear implant in future.

Techniques that you will learn:
* Hearing threshold measurements
* Histological processing of the cochlea
* Immunohistochemistry
* 3D reconstructions
* Light, fluorescence and fluorescence confocal imaging
* Statistical analyses of data.

Changing ion channel expression in the auditory nerve

Supervisor: Dr Karina Needham

Project suitability: Advanced Medical Science, Honours, Masters, Ph.D

The cochlear implant is able to overcome hearing impairment by providing electrical stimulation direct to the neurons of the auditory nerve.  The ability of these auditory neurons to respond to such electrical inputs is dependent upon the composition and activity of certain ion channels within their plasma membrane.  As the expression of ion channels can be influenced by a number of factors, including neuronal injury, inflammation and levels of neurotrophins (nerve growth factors), evidence of differences in the response characteristics of the auditory nerve in hearing and deafness suggest a shift in ion channel expression.  The current study will examine how deafness and therapeutic interventions such as neurotrophin-replacement influence ion channel expression in the auditory nerve.

 Techniques that you will learn:
* Immunohistochemistry
* Patch-clamp electrophysiology
* Surgical and micro-dissection techniques
* Light microscopy and fluorescence imaging
* Tissue sectioning 

Cortical plasticity and connectivity - Chronic recordings

Project suitability:  Advanced Medical Science, Honours, Ph.D 

All modern cochlear implants rely on the organisational structure of the auditory pathway to provide cues for speech perception. The structure of the auditory pathway is controlled by both genetic cues and auditory experience, and in deaf individuals the lack of acoustic input results in a more rudimentary pathway. We have previously shown that chronic cochlear implant use, from a very young age, can ameliorate many of the deafness-induced changes in the auditory pathway (Fallon et al., 2009). It is this ability of the auditory pathway to undergo plastic reorganization that is a major factor underlying the clinical success of cochlear implants. However, there are critical periods before which the auditory system must be activated to achieve the best clinical outcomes. This project therefore aims to examine how the auditory pathway changes and reorganises over time with long-term deafness and chronic cochlear implant use. Our previous method of taking a single ‘snap shot' of the auditory brain is not suitable to address these issues; we are therefore developing the ability to perform repeated chronic recordings from the auditory brain. Data from these experiments will assist the clinical decision-making processes concerned with the optimum time for cochlear implantation, and the best forms of rehabilitation and training given to cochlear implant patients. Ultimately, the results of this project should lead to improvements in the quality of auditory perception for cochlear implant patients.

 
Techniques that you will learn:
* General surgical skills including sterile techniques
* Electrophysiological recordings
* Light microscopy
* Imaging and analysis
* Statistical analysis of results

Cochlear implants and residual hearing

Supervisors: Dr James Fallon & Dr Andrew Wise, Prof Dexter Irvine, Prof Rob Shepherd

Project suitability: Advanced Medical Science, Honours, PhD

Modern cochlear implants have proven to be such an effective treatment for profoundly deaf individuals, that patients with significant amounts of residual, low frequency, hearing are now being implanted. We have extensive experience in studying the effects of long-term cochlear implant use in a range of models of profound deafness; however, there has been little study of the effects of long-term cochlear implant use on residual hearing. Therefore, in this project we will examine the effects of long-term cochlear implant use on residual low frequency hearing using a range of electrophysiological and anatomical techniques..

Techniques that you will learn:
* General surgical skills including sterile techniques
* Electrophysiological recordings
* Immunofluorescent staining
* Fluorescent and light microscopy
* Imaging and analysis
* Statistical analysis of results

Directed training for improved cochlear implant performance

Supervisor: Dr James Fallon, Prof Dexter Irvine, Prof Rob Shepherd

Project suitability: Advanced Medical Science, Honours, PhD

Prolonged periods of profound deafness from a young a,ge result in the central auditory pathway developing in an abnormal way. We have previously shown that long-term cochlear implant use can ameliorate many of these deafness induced changes (Fallon et al., 2009). We are now interested in the effects of different types of training with cochlear implants on the development of the central auditory pathway. This project will develop techniques to provide directed training, in a model of cochlear implant use, aimed to further ameliorate the deafness induced changes. The effectiveness of the training will be assessed using behavioural, electrophysiological and anatomical techniques.

Techniques that you will learn:
* General surgical skills including sterile techniques
* Behavioural training
* Electrophysiological recordings
* Immunofluorescent staining
* Fluorescent and light microscopy
* Imaging and analysis
* Statistical analysis of results

Real Time simulator of bimodal and hybrid hearing devices

Suervisor: Dr Jeremy Marozeau

Project suitability: Honours, Engineering student Project, PhD

The project will result in the implementation of a bimodal hearing device simulator program. The simulator will take microphone or audio input, and process audio in real time, providing a simulation of how a listener with a cochlear implant (CI), hearing aid (HA), or hybrid device (CA+HA) in one or both ears may perceive sound. This simulator will run in real-time on a PC equipped with a microphone or line-in. It will be implemented in JAVA in the MAX/MSP environment. It will be highly parametric, letting the user easily change the mapping, the sound processing strategy and hearing-aid parameters. Any change will be effective in real time, letting the user fully appreciate the effect of each parameter change. The accuracy of the simulator will be evaluated by patients with unilateral losses (one ear with impaired hearing + one ear with normal hearing).

This simulator is useful for 3 main reasons:
1] In order to improve music perception, it is important to understand how the sound quality depends on physical parameters (pulse rate, number of channels ...).
2] Bimodal and hybrid stimulation is currently under investigation as a better approach to improve music appreciation. This simulator will be useful to evaluate this approach.
3] The music perception team is currently working with a composer to organise a concert with music made especially for people with impaired hearing. This simulator will be very beneficial for the composers, who will be able to test various compositions in real time.

Techniques that you will learn:
* Running Psychoacoustic experiments
* Sound editing and mixing
* Software as Max/MSP and Matlab
* Hearing impairment simulation
* Statistical analysis of data
* Recruitment Subjects
* Real time audio programming

Gene transfer technology for maintaining and regenerating auditory nerves after hearing loss

Supervisor: Dr Rachael Richardson

Project suitability: Honours, PhD

Many types of deafness result in progressive degeneration of auditory neurons. Experimental research has proven that providing neurotrophins to the cochlea can maintain auditory neuron survival for short periods of time. We are now interested in methods of promoting longer-term nerve survival and more controlled regeneration using gene transfer technology. This project will use in vitro tissue culture (see picture) and in vivo surgical techniques to investigate gene transfer in the cochlea. The genes for brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) have been placed in adeno-associated virus and adenoviral vectors. Viral particles containing the BDNF or NT3 genes will then be added to the cultures or to the cochleae of guinea pigs in order to investigate the effect of neurotrophin gene expression on nerve survival and regeneration after sensorineural hearing loss.

Techniques that you will learn:
* Micro-dissection
* Micro-surgery
* Sterile technique
* Primary tissue culture
* Molecular biology techniques eg DNA amplification.
* Immunofluorescent staining
* Fluorescent and light microscopy
* Imaging and analysis
* Statistical analysis of results

Development of a paediatric quality of life assessment tool for children with hearing loss

Supervisor: Dr Julia Sarant

Project suitability: PhD (applicant should have a clinical background related to children/hearing)

Measures beyond psychophysical and perceptual-based outcomes are needed in order to answer questions about the relative benefits of one versus two cochlear implants, and also of two cochlear implants versus a bimodal fitting (cochlear implant plus hearing aid) in terms of management recommendations for children with severe-profound hearing loss. This project involves developing a specialised quality of life (related to hearing) measure to be used with children participating in a 5-year longitudinal project across four states investigating broader outcomes of bilateral versus unilateral cochlear implants. The reliability and validity of the tool will be tested, it will be used to collect data for children participating in the the longitudinal project, and the data obtained will contribute to an economic cost-benefit analysis of bilateral versus unilateral cochlear implants.

It is expected that collaboration with the Psychology Department and the School of Population Health will occur throughout the conduct and supervision of this project.

The effects of trophic agents on the auditory nervous system

Supervisors: Dr David Sly, Professor Stephen O'Leary

Project suitability:  Advanced Medical Science, Honours, Masters, Ph.D, Master of Audiology Research Project

Cochlear implants restore hearing by direct electrical stimulation of the auditory (hearing) nerves. The success of the implant is therefore dependent upon the integrity and function of these nerves. In a healthy ear, the auditory nerve is normally maintained by the release of nerve growth factors from hair cells, but when these are lost in deafness, there is severe degradation of the auditory nerve with time. However, the application of nerve growth factors to the deafened cochlea arrests hearing nerve degeneration and is potentially of major importance to cochlear implantation.

This NHMRC funded project examines how biological interventions with nerve growth factors can affect the structure of the auditory nerve and its response to cochlear implant stimulation. We are particularly interested in working out how longer periods of deafness and neurotrophin treatment and varying dosages of neurotrophins affect these outcomes in the hope that they may be understood prior to clinical application of nerve growth factors.

Techniques that you will learn:

* Diverse range from anatomy, physiology, surgery, computers & electronics
* Cochlear implant surgery
* Single neuron electrophysiology
* Cochlea and auditory brain anatomy and histology
* Fluorescent and light microscopy
* Data analysis

Electrophonic hearing with a cochlear implant

Supervisor: Dr David Grayden

Project suitability: Masters, Ph.D

Electrophonic hearing results from vibrations in the inner ear caused by electrical stimulation. These vibrations can eliciting hearing. Recently, some cochlear implant users have usable low-frequency hearing in the same ear as their implant. This project will investigate using the cochlear implant to generate electrophonic hearing in the low frequencies that will provide improved speech recognition, sound localisation and music perception to users.

Fine-grained timing information for cochlear implants

Supervisor: Dr David Grayden

Project suitability: Masters, Ph.D

Current cochlear implants use coarse frequency and timing information to convey sounds to users. Higher rates of stimulation are now possible with modern cochlear implants, so it is possible to provide more fin-grained timing cues by precisely controlling the time of stimulation. This project will investigate algorithms for controlling timing cues so provide stimulation that may help users to better perceive speech in noisy situations and better perceive music.

Modelling the auditory nerve response to cochlear implant stimulation: improving speech processors

Supervisors: Leon Heffer, Dr David Sly, Professor Stephen O'Leary

Project suitability: Advanced Medical Science, Honours, Master of Audiology Research Project, Undergraduate Research Opportunity Program

This project stems from our recent success at developing a mathematical model that can accurately predict the firing responses of single auditory neurons to complex electrical stimulation. This model has far-reaching implications for speeding the development and improvement for all types of neural prostheses, including the cochlear implant.

The project will investigate:

Testing and refinement of the model using different types of patterned electrical stimuli.
Expansion of the model to include a desired target response (the response to acoustical stimulation).
Testing the model in deafened animals to determine whether degenerating nerves perform similarly to healthy nerves.
Testing the model in human cochlear implant recipients.
The applicant will ideally have a keen interest in neuroscience, computer programming, mathematics and electronics.

Techniques you will learn:
* Laboratory and clinical setting experience 
* Cross disciplinary research (neuroscience, surgery, engineering, behavioural science)

Preventing hearing loss during surgery to the ear

Supervisor: Professor Stephen O'Leary

Project suitability: Advanced Medical Science, Honours, Doctor of Medicine, Ph.D, Master ofAudiology Research Project, Undergraduate Research Opportunity Program

This NHMRC funded project aims to reduce the risk of hearing loss duringsurgery or medical interventions, such as chemotherapy to treat cancer.Hearing loss during cochlear implantation is of particular interest,since the aim of implant surgery is now to combine both natural hearingand the cochlear implant. This is a translational research project thatis defining clinically applicable ways of delivering protective drugsto the inner ear prior to medical and surgical interventions. Weconduct basic research into the modes and timing of delivery oftherapeutic drugs to the inner ear, and clinical trials. This projectwould suit those with an interest in surgery, clinical medicine,audiology, hearing sciences ir boimedical engineering.

Virtual reality surgery

Supervisor: Professor Stephen O'Leary

Project suitablility: Advanced Medical Science, Honours, Doctor of Medicine, Ph.D, Master of Audiology Research Project, Undergraduate Research Opportunity Program

Virtual reality (VR) surgery is the way in which surgeons of tomorrow will be taught. VR surgery involves immersion into a 3D world where the patient can be touched and operated on. The Department of Otolaryngology has developed a virtual reality surgical environment for ear surgery, which has been commercialised by the Australian company, Medic Vision, and was the recipient of the University's Knowledge Transfer Award for 2008. We are involved in exciting research that will determine how best to train surgeons in VR, and provide real-time feedback to trainees. This research will interest to students with an interest in surgery, or computer science. 

Repairing the auditory system with cochlear implantation and drug delivery

Supervisor: Dr Andrew Wise, Prof Rob Shepherd

Project suitability: Advanced Medical Science, Honours, PhD

A common cause of deafness is the loss of sensory hair cells (green cells shown in the normal cochlea, figure 1A) in the cochlea that normally convert sound into nerve impulses. The cochlear implant works by electrically exciting auditory nerves (red figure 1A) directly to bypass the sensory hair cells that are either damaged or absent. However, auditory nerves degenerate after deafness (figure 1B) leading to a significant reduction in their population and changes in their responses to electrical stimulation. The administration of growth factors can prevent nerve degeneration and even promote resprouting of the nerve endings (figure 1B). The aim of this research project is to prevent this degenerative process and restore function to the deaf cochlea using a cochlear implant and/or with the delivery of neuroprotective drugs.

Techniques that you will learn:
* Micro-surgery and cochlear implantation
* Electrophysiological recordings from the auditory pathway
* Immunohistochemical staining
* Confocal and light microscopy
* Data and image analysis
* Statistical analysis