CANCELLED: Perspectives from a long career in Hearing Research  Seminar

Perspectives from a long career in Hearing Research  - ISVR Hearing and Balance Centre Research Seminar
A week is a long time in politics and 40 years is a very very long time in hearing research.  When I began my career the vibration patterns of the basilar membrane were thought to be broadly tuned, cochlear implantation had not been attempted and oto-acoustic emissions had yet to be discovered. The pace of discovery has been such that to survive and thrive in research over this period it has been necessary to continuously innovate and reinvent oneself.  Over the years, my research group has explored a number of brain regions in several species and I will briefly describe some of the contributions that we have made to a number of diverse areas of hearing science such as OAEs, neurophysiology and fMRI.  That done, I will focus in more detail a couple of these contributions in areas that are still somewhat controversial.  The first of these is binaural hearing and the second is the sharpness of tuning in the human cochlea.

The two major cues for binaural localisation of sounds are interaural level and time differences. It now appears that decoding both interaural level difference and interaural time difference cues for localizing a sound may involve similar non-topographic population codes which vary in complementary ways in each hemisphere.

Whether human cochlear tuning is sharper than that of animal models remains controversial.  Part of this uncertainty rests upon the indirect methods that are used to estimate such tuning from oto-acoustic emissions.  By using a single animal model and estimating tuning from auditory nerve measurements, oto-acoustic emissions and psychophysical measurements we concluded that the human cochlea is most likely to be more sharply tuned that other animals.