Non-linear cochlear mechanics: Models and measurements

About the project

The mechanical response of the cochlea to sound exhibits an intriguing array of different non-linear phenomena, involving interactions across time and frequency. These remain poorly understood but can be assessed using otoacoustic emissions (OAEs): low-level sounds detectable in the ear canal.

OAEs are measured by presenting sound stimuli to the ear and measuring the response.
Though they are currently used in certain clinical applications (such as diagnosing cochlear impairments in newborn babies), many questions remain:

How do features in the OAE signal relate to processes and pathologies within the cochlea?
What is the optimum stimulus and recording method for assessing different cochlear impairments in different patients (e.g., children)?

This project will explore:

Mathematical models of non-linear cochlear mechanics that underly the generation of different classes of OAEs.
The design of stimulus and recording paradigms to optimise clinically relevant features of OAEs.
Measurements of OAEs in human volunteers using different recording paradigms.

Potential supervisors

Lead supervisor

Dr Ben Lineton

Associate Professor

Research interests

Much of cochlear physiology and pathophysiology remains poorly understood. For example, how do the 3000 rows of active outer hair cells interact with each other and with other cochlear structures to amplify the waves in the cochlea that allow us to hear? How are the motions of these cochlear structures related to the otoacoustic emissions that we can measure in the ear canal? What role do the efferent nerves play? What are the changes brought about by pathology? The long term research goal is to understand human cochlear physiology in both normal and pathological conditions with a view to aiding the development of improved clinical diagnostic techniques and treatments. One approach to improving our understanding of the electro-mechanical aspect of physiology is to develop realistic models of the cochlea. These should capture the essential hydrodynamics, structural dynamics, and electrical processes involved in cochlear physiology. The non-linear mechano-electrical and electro-mechanical transduction processes are key aspects of the physiology where our understanding remains at a basic level. The ways in which these models may be useful clinically are: to aid the development of treatments, or prostheses for hearing impairment, to improve our ability to interpret clinical results (such as measurements of otoacoustic emissions or electrophysiology), to aid the development of new clinical tests of cochlear function.

Entry requirements

A UK 2:1 honours degree, or its international equivalent.

Fees and funding

Funding for tuition fees and a stipend (living allowance) are available on a competitive basis. Funding will be awarded on a rolling basis, so apply early for the best opportunity to be considered.

How to apply

Apply now

You need to:

choose programme type (Research), 2024/25, Faculty of Engineering and Physical Sciences
choose PhD Engineering & Environment (Full time)
add supervisor Ben Lineton in section 2

Applications should include:

your CV (resumé)
research proposal
2 reference letters
degree transcripts to date

Contact us

Faculty of Engineering and Physical Sciences

If you have a general question, email our doctoral college (feps-pgr-apply@soton.ac.uk).

Project leader

For an initial conversation, email Ben Lineton (bl@isvr.soton.ac.uk)

Postgraduate research project