title: Detection of acoustic temporal fine structure by cochlear implant listeners: behavioral results and computational modeling.
abstract: A test of within-channel detection of acoustic temporal fine structure (aTFS) cues is presented. Eight cochlear implant listeners (CI) were asked to discriminate between two Schroeder-phase (SP) complexes using a two-alternative, forced-choice task. Because differences between the acoustic stimuli are primarily constrained to their aTFS, successful discrimination reflects a combination of the subjects' perception of and the strategy's ability to deliver aTFS cues. Subjects were mapped with single-channel Continuous Interleaved Sampling (CIS) and Simultaneous Analog Stimulation (SAS) strategies. To compare within- and across- channel delivery of aTFS cues, a 16-channel clinical HiRes strategy was also fitted. Throughout testing, SAS consistently outperformed the CIS strategy (p ≤ 0.002). For SP stimuli with F0 = 50 Hz, the highest discrimination scores were achieved with the HiRes encoding, followed by scores with the SAS and the CIS strategies, respectively. At 200 Hz, single-channel SAS performed better than HiRes (p = 0.022), demonstrating that under a more challenging testing condition, discrimination performance with a single-channel analog encoding can exceed that of a 16-channel pulsatile strategy. To better understand the intermediate steps of discrimination, a biophysical model was used to examine the neural discharges evoked by the SP stimuli. Discrimination estimates calculated from simulated neural responses successfully tracked the behavioral performance trends of single-channel CI listeners.
authors: Department of Bioengineering, University of Washington, Seattle, WA 98195, USA. imennov@u.washington.edu
authors: Nikita S
authors: NS
authors: Imennov
authors: Jong Ho
authors: JH
authors: Won
authors: Ward R
authors: WR
authors: Drennan
authors: Elyse
authors: E
authors: Jameyson
authors: Jay T
authors: JT
authors: Rubinstein
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001299:Audiometry; D001307:Auditory Perception; D001309:Auditory Threshold; D019929:Cochlear Implantation / Q000295:instrumentation*; D003054:Cochlear Implants; D003198:Computer Simulation; D012048:Correction of Hearing Impairment / Q000523:psychology*; D003463:Cues; D004192:Discrimination, Psychological; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D011571:Psychoacoustics; D013997:Time Factors; D013998:Time Perception