title: Simulating electrical modulation detection thresholds using a biophysical model of the auditory nerve.
abstract: Modulation detection thresholds (MDTs) assess listeners' sensitivity to changes in the temporal envelope of a signal and have been shown to strongly correlate with speech perception in cochlear implant users. MDTs are simulated with a stochastic model of a population of auditory nerve fibers that has been verified to accurately simulate a number of physiologically important temporal response properties. The procedure to estimate detection thresholds has previously been applied to stimulus discrimination tasks. The population model simulates the MDT-stimulus intensity relationship measured in cochlear implant users. The model also recreates the shape of the modulation transfer function and the relationship between MDTs and carrier rate. Discrimination based on fluctuations in synchronous firing activity predicts better performance at low carrier rates, but quantitative measures of modulation coding predict better neural representation of high carrier rate stimuli. Manipulating the number of fibers and a temporal integration parameter, the width of a sliding temporal integration window, varies properties of the MDTs, such as cutoff frequency and peak threshold. These results demonstrate the importance of using a multi-diameter fiber population in modeling the MDTs and demonstrate a wider applicability of this model to simulating behavioral performance in cochlear implant listeners.
authors.affiliation: Department of Otolaryngology, V. M. Bloedel Hearing Research Center, University of Washington, Box 3657923, CHDD building, CD 176, Seattle, Washington 98196, USA.
authors.forename: Gabrielle E
authors.initials: GE
authors.lastname: O'Brien
authors.affiliation: Department of Otolaryngology, V. M. Bloedel Hearing Research Center, University of Washington, Box 3657923, CHDD building, CD 176, Seattle, Washington 98196, USA.
authors.forename: Nikita S
authors.initials: NS
authors.lastname: Imennov
authors.affiliation: Department of Otolaryngology, V. M. Bloedel Hearing Research Center, University of Washington, Box 3657923, CHDD building, CD 176, Seattle, Washington 98196, USA.
authors.forename: Jay T
authors.initials: JT
authors.lastname: Rubinstein
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001309:Auditory Threshold; D002415:Cats; D003054:Cochlear Implants; D003056:Cochlear Nerve / Q000503:physiopathology*; D003198:Computer Simulation; D003463:Cues; D004558:Electric Stimulation; D005072:Evoked Potentials, Auditory; D006801:Humans; D008959:Models, Neurological; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D010898:Pitch Perception; D017603:Signal Detection, Psychological; D013067:Speech Perception; D013269:Stochastic Processes; D013997:Time Factors