title: Development of a temporal fundamental frequency coding strategy for cochlear implants.
abstract: A sound-coding strategy for users of cochlear implants, named enhanced-envelope-encoded tone (eTone), was developed to improve coding of fundamental frequency (F0) in the temporal envelopes of the electrical stimulus signals. It is based on the advanced combinational encoder (ACE) strategy and includes additional processing that explicitly applies F0 modulation to channel envelope signals that contain harmonics of prominent complex tones. Channels that contain only inharmonic signals retain envelopes normally produced by ACE. The strategy incorporates an F0 estimator to determine the frequency of modulation and a harmonic probability estimator to control the amount of modulation enhancement applied to each channel. The F0 estimator was designed to provide an accurate estimate of F0 with minimal processing lag and robustness to the effects of competing noise. Error rates for the F0 estimator and accuracy of the harmonic probability estimator were compared with previous approaches and outcomes demonstrated that the strategy operates effectively across a range of signals and conditions that are relevant to cochlear implant users.
authors.affiliation: The Hearing CRC, 550 Swanston Street, Carlton 3053, Melbourne, Victoria, Australia. andrewev@unimelb.edu.au
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Vandali
authors.forename: Richard J M
authors.initials: RJ
authors.lastname: van Hoesel
mesh_terms: D000161:Acoustic Stimulation; D001309:Auditory Threshold; D019929:Cochlear Implantation / Q000295:instrumentation*; D003054:Cochlear Implants; D012048:Correction of Hearing Impairment / Q000523:psychology; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D011474:Prosthesis Design; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception; D013997:Time Factors