Interim Thoughts on Cochlear Tissues, Neural/Behavioral Models, and Encoding

Abstract

Principal questions and challenges facing the field of neural and behavioral modeling of the electrically stimulated ear have been well described by Smoorenburg, van den Honert, Hartmann and Klinke, Pfingst, and Shannon in this volume. There is a clear need for additional data on fundamental issues concerning electrically generated perceptual space and hearing abilities provided by electrical stimulation, the development of this space(s), and the dependency of its characteristics on encoding strategies used to excite eighth nerve fibers, the state of the temporal bone, previous abilities and experiences of the patient, and much more. At a physiological level, we must further define the response features of auditory nerves in the normal and pathological preparation to electrical stimulation, define the dynamic range of function of the system with different stimulation configurations, test strategies for mimicking acoustical response properties with electrical stimuli, and define the important questions to ask high centers of the auditory system regarding the processing of complex signals. As well, issues must be addressed of how we will relate physiological observations to behavioral data, e.g., why the synchrony characteristics of auditory cells observed in response to high-frequency electrical stimuli do not lead to better high-frequency discrimination and pitch perception.