Prof Jennifer Linden (Ear Institute)
Proposed PhD project:
Prof Jennifer F. Linden (Ear Institute)
Prof Maneesh Sahani (Gatsby Computational Neuroscience Unit)
Prof Stuart Rosen (Speech, Hearing & Phonetic Sciences)
Project Title: The Importance of Hearing the Ending
Understanding speech in noisy environments is one of the most difficult tasks in hearing, especially for children with developmental disorders and for elderly adults. Difficulty understanding speech in noise can occur even when peripheral hearing is completely normal, and therefore is thought to arise at least in part from abnormalities within the auditory brain beyond the ear. Recent studies in mouse models of developmental disorders have suggested that one such abnormality may be a specific reduction in auditory brain responses to offsets (disappearances) of sounds. The aim of this PhD project is to analyze the role of sound-offset sensitivity in perception of complex sounds such as speech in noise, through psychophysical testing of young and old human subjects with or without developmental disorders. A further goal is to determine what manipulations of acoustic signals increase the perceptual salience of sound offsets, and how those manipulations affect ability to understand speech in noisy environments.
This project will involve co-supervision by an interdisciplinary team of supervisors from across UCL. Prof Jennifer Linden (Ear Institute) is an auditory neuroscientist studying central auditory abnormalities in mouse models of developmental disorders. Prof Maneesh Sahani (Gatsby Computational Neuroscience Unit) is a theoretical and computational neuroscientist studying the mechanisms of perceptual inference and the statistical structure of natural sounds. Prof Stuart Rosen (Speech, Hearing & Phonetic Sciences) is an auditory psychophysicist and speech scientist studying auditory processing of speech and non-speech sounds in normal subjects, hearing-impaired subjects, and people with developmental disorders; he is also an expert on signal processing for cochlear implants.
The project fits perfectly within the remit of the SenSyT PhD programme because it is fundamentally interdisciplinary and has significant translational potential. This investigation of the perceptual importance of sound-offset sensitivity will draw upon the expertise of all three of the supervisors, to test a hypothesis emerging from basic auditory neurophysiology through studies of natural sound statistics and human speech perception. Furthermore, the results of this work may suggest new approaches to signal processing in cochlear implants that could improve patients' ability to understand speech in noisy environments.