Are cochlear implant patients suffering from perceptual dissonance?
Cochlear implants provide functional hearing to the majority of recipients and have gained widespread acceptance clinically, but the range of performance remains great and largely unexplained. Designs for implanted electrodes and electronics have converged, whereas novel speech processing strategies have proliferated. For each patient, the fitting audiologist must sort empirically through options that produce large but idiosyncratic differences in both objective performance and subjective preference. This review and analysis suggests that the place-pitch and rate-pitch theories on which cochlear implants have been designed are incomplete. The missing component may be related to the phase-locking of auditory nerve activity to both acoustic and electrical stimulation. This component is likely to be highly distorted by electrical stimulation but its importance as one of several different pitch encoding mechanisms may vary widely among patients. Systematic means to control these putative phase effects using modern, high-speed, and high-density cochlear implants may make it possible to identify more efficiently the best strategy for a given patient and to minimize the perceptual confusion that arises from conflicting cues.
Loeb
Gerald E
GE
Department of Biomedical Engineering, Viterbi School of Engineering and A. E. Mann Institute for Biomedical Engineering, University of Southern California, Los Angeles 90089-1112, USA. gloeb@usc.edu
D000161:Acoustic Stimulation; D001307:Auditory Perception / Q000502:physiology; D003054:Cochlear Implants / Q000009:adverse effects / Q000592:standards*; D003056:Cochlear Nerve / Q000502:physiology*; D003073:Cognitive Dissonance; D003463:Cues; D004558:Electric Stimulation; D034381:Hearing Loss / Q000534:rehabilitation; D006801:Humans; D010468:Perceptual Disorders / Q000209:etiology* / Q000503:physiopathology; D010469:Perceptual Distortion / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology