Seminar: 2/23 - Brian Moore
11:00 to 12:30 PM at:
Dept. of Experimental Psychology
University of Cambridge
"The role of temporal fine structure in pitch perception and speech perception."
Broadband complex sounds such as music and speech are decomposed by the cochlea into a series of narrowband signals, each corresponding to the waveform at a specific place on the basilar membrane. Each signal can be considered as composed of a “carrier” (the temporal fine structure, TFS) with a fluctuating envelope, E. In the auditory nerve, the TFS is represented in the detailed timing of neural impulses (phase locking), while the E is represented by fluctuations in firing rate over time. In this talk, I will review evidence supporting the idea that TFS plays an important role in pitch perception and in speech perception. TFS may be especially important when listening to a target talker in the presence of one or more background talkers. People with cochlear hearing loss have a reduced ability to process TFS, and people with cochlear implants have almost no ability to process TFS. This can partly account for their poor pitch perception and poor abilities to understand speech when background sounds are present.