Listening Effort and Speech Encoding in Cochlear Implant Users
Because of the degraded auditory signal, CI users commonly report that using their device, especially during rehabilitation, is effortful. Listening effort places a large demand on global cognitive resources, impinging on processing speed, attention and working memory, ultimately making it harder for a CI user to navigate the sensory world. I am developing objective electrophysiological measures of listening effort by measuring EEG oscillations, and relating these oscillations to neural encoding of naturalistic speech. The goal is to develop tools that can tell a clinician if a CI user is exerting particularly high effort—important information that is not captured in speech tests and audiometry.
Tinnitus is the phantom perception of a sound for which there is presently no cure or effective treatment. My research in tinnitus has focused on three areas: (i) objective diagnosis of tinnitus for use in humans and validating animal models (ii) relationship of tinnitus to cochlear synaptopathy (iii) the relationship of tinnitus and the ability to attend to sounds in the environment.
Noise exposure can lead to permanent damage of synapses that link cochlear hair cells to the auditory nerve, but leave hair cell function intact. For this reason synaptic damage can go undetected from standard clinical tests of thresholds, such as the audiogram, although individuals with cochlear synaptopathy may report difficulty with listening in noise or with competing sources. I am working on behavioural and electrophysiological tests, interpreted through computational modeling of the inner ear, that can detect “hidden” synaptic losses in individuals with otherwise clinically “normal” hearing.
The Perception of Music, Rhythm, and Timing
In a previous life I explored music, emotions, and the perception of rhythm and timing. Please see publications for more information.