Pitch perception in acoustic and electric hearing: Hunting down the missing fundamentals

Abstract:

Pitch perception is important not only for the enjoyment of music and for the perception of prosody in speech, but also for our ability to process one sound, such as a voice, in the presence of competing sounds. Poor pitch perception, and the resulting difficulties when listening in noisy situations, are a common source of disability in deaf patients whose hearing has been restored by a cochlear implant (CI). I will summarise some experiments that address the following questions;

• What aspects of the auditory-nerve response to sound are crucial for good pitch perception by normal hearing (NH) listeners?
• What is the biological basis for the severe limitations in pitch perception experienced by CI users?
• Are these limits fixed, or can they be partially overcome by the chronic electrical stimulation that occurs in the months following activation of a patient’s CI?,
• Can pitch perception by CI users be improved by a drug that modulated fast-acting potassium channels?

The experiments involve a combination of NH psychoacoustics, investigation of an illusory percept, CI psychophysics, electrophysiological recordings, and the results of a double-blind placebo-controlled drug trial. I will also briefly describe other experiments from our lab that aim to improve hearing by CI listeners.