SEMINAR: Mechanisms of auditory attention in normal and hearing impaired listeners

"Rites of Passage" Seminar

The Seminar: : In an effect known as the attentional filter, quiet tones that are presented in background noise are more detectable if they are presented at frequently occurring expected frequencies over rarely occurring unexpected frequencies. Previous research has implicated a subcortical auditory structure known as the medial olivocochlear system (MOCS) in the formation of the attentional filter. In this thesis, the suggested role for the MOCS in forming the attentional filter was tested in individuals with normal hearing and in individuals with hearing impairments that are associated with reduced MOCS efferent action on hearing. No direct support for the MOCS forming the attentional filter was found in individuals with normal hearing. However, the attentional filter was consistently impaired in individuals with hearing losses associated with reduced MOCS efferent action on hearing, which is consistent with its suggested role. Finally, at least one cochlear implant user, in whom there could be no MOCS efferent action on hearing, formed a normal attentional filter, which strongly suggests the presence of an alternative, likely central mechanism that is able to form the filter.

The Speaker: Christo been based in the Auditory Lab in Physiology since he started his BSc (Hons) in 2010. He was supervised by E/Prof Don Robertson and Dr Helmy Mulders. During his PhD he changed his research model from guinea pigs to humans, so while E/Prof Don Robertson continued to supervise him, he was also co-supervised by E/Prof Geoff Hammond from the School of Psychology.