title: Loudness of time-varying stimuli with electric stimulation.
abstract: McKay, Henshall, Farrell, and McDermott [J. Acoust. Soc. Am. 113, 2054-2063 (2003)] developed a practical method to estimate the loudness of periodic electrical signals presented through a cochlear implant. In the present work, this method was extended to time-varying sounds based on two models of time-varying loudness for normal listeners. To fit the model parameters, loudness balancing data was collected with six cochlear implant listeners. The pulse rate of a modulated pulse train was adjusted to equalize its loudness to a reference stimulus. The stimuli were single-electrode time-limited pulse bursts, repeated at a rate of 50 Hz, with on-times varying between 2 and 20 ms. The parameters of two different models of time-varying loudness were fitted to the results. For each model, parameters defining the time windows over which the electrical pulses contribute to instantaneous loudness were optimized. In each case, a good fit was obtained with the loudness balancing results. Therefore, the practical method was successfully extended to time-varying sounds by combining it with existing models of time-varying loudness for acoustic stimulation.
authors.affiliation: ExpORL, Department of Neurosciences, KU Leuven, Herestraat 49 bus 721, B-3000 Leuven, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Francart
authors.affiliation: The Bionics Institute, 384-388 Albert Street, East Melbourne, Victoria 3002, Australia.
authors.forename: Hamish
authors.initials: H
authors.lastname: Innes-Brown
authors.affiliation: The Bionics Institute, 384-388 Albert Street, East Melbourne, Victoria 3002, Australia.
authors.forename: Hugh J
authors.initials: HJ
authors.lastname: McDermott
authors.affiliation: The Bionics Institute, 384-388 Albert Street, East Melbourne, Victoria 3002, Australia.
authors.forename: Colette M
authors.initials: CM
authors.lastname: McKay