Is there a fundamental 300 Hz limit to pulse rate discrimination in cochlear implants?

Show simple item record Venter, Pieter J. Hanekom, Johannes Jurgens 2015-09-02T05:48:37Z 2015-09-02T05:48:37Z 2014-10
dc.description.abstract Literature often refers to a 300 pps limit for cochlear implant (CI) electrical stimulation above which pulse rate discrimination deteriorates or above which rate pitch is not perceived to increase. The present study investigated the effect on pulse rate difference limens (PRDLs) when using compound stimuli in which identical pulse trains were applied to multiple electrodes across the length of the electrode array and compares the results to those of single-electrode stimuli. PRDLs of seven CI users were determined in two stimulus pulse phase conditions, one in which the phase delays between pulses on different electrodes were minimized (burst mode) and a second in which they were maximized (spread mode). PRDLs were measured at base rates of 100 pps to 600 pps in 100 pps intervals, using compound stimuli on one, two, five, nine and 18 electrodes. As smaller PRDLs were expected to reflect improved rate pitch perception, 18-electrode spread mode stimuli were also included in a pitch ranking task. PRDLs improved markedly when multi-electrode compound stimuli were used, with average spread mode PRDLs across listeners of between 6 and 8% of the base rate in the whole range tested (i.e., up to 600 pps). PRDLs continued to improve as more electrodes were included, up to at least nine electrodes in the compound stimulus. Stimulus pulse phase had a significant influence on the results, with PRDLs being smaller in spread mode. Results indicate that pulse rate discrimination may be manipulated with stimulus parameter choice, so that previously-observed deterioration of PRDLs at 300 pps probably does not reflect a fundamental limitation to rate discrimination. However, rate pitch perception did not improve in the conditions that resulted in smaller PRDLs. This may indicate that listeners used cues other than pitch to perform the rate discrimination task, or may reflect limitations in the electrically-evoked neural excitation patterns presented to a rate pitch extraction mechanism. en_ZA
dc.description.embargo 2015-10-31 en_ZA
dc.description.librarian hb2015 en_ZA
dc.description.sponsorship National Research Foundation (South Africa) en_ZA
dc.description.uri en_ZA
dc.identifier.citation Venter, PJ & Hanekom, JJ 2014, 'Is there a fundamental 300 Hz limit to pulse rate discrimination in cochlear implants?', Journal of the Association for Research in Otolaryngology, vol. 15, no. 5, pp. 849-866. en_ZA
dc.identifier.issn 1525-3961 (print)
dc.identifier.issn 1438-7573 (online)
dc.identifier.other 10.1007/s10162-014-0468-6
dc.language.iso en en_ZA
dc.publisher Springer en_ZA
dc.rights © 2014 Association for Research in Otolaryngology. The original publication is available at : http://link.springer.comjournal/10162. en_ZA
dc.subject Rate pitch en_ZA
dc.subject Rate discrimination thresholds en_ZA
dc.subject Multielectrode stimuli en_ZA
dc.subject Across-channel integration en_ZA
dc.subject Cochlear implant (CI) en_ZA
dc.subject Pulse rate difference limens (PRDLs) en_ZA
dc.title Is there a fundamental 300 Hz limit to pulse rate discrimination in cochlear implants? en_ZA
dc.type Postprint Article en_ZA

Files in this item

This item appears in the following Collection(s)

Show simple item record