Resistance to learning binaurally mismatched frequency-to-place maps: Implications for bilateral stimulation with cochlear implants.
Journal of the Acoustical Society of America
1645 - 1660.
Available under License : See the attached licence file.
Simulations of monaural cochlear implants in normal hearing listeners have shown that the deleterious effects of upward spectral shifting on speech perception can be overcome with training. This study simulates bilateral stimulation with a unilateral spectral shift to investigate whether listeners can adapt to upward-shifted speech information presented together with contralateral unshifted information. A six-channel, dichotic, interleaved sine-carrier vocoder simulated a binaurally mismatched frequency-to-place map. Odd channels were presented to one ear with an upward frequency shift equivalent to 6 mm on the basilar membrane, while even channels were presented to the contralateral ear unshifted. In Experiment 1, listeners were trained for 5.3 h with either the binaurally mismatched processor or with just the shifted monaural bands. In Experiment 2, the duration of training was 10 h, and the trained condition alternated between those of Experiment 1. While listeners showed learning in both experiments, intelligibility with the binaurally mismatched processor never exceeded, intelligibility with just the three unshifted bands, suggesting that listeners did not benefit from combining the mismatched maps, even though there was clear scope to do so. Frequency-place map alignment may thus be of importance when optimizing bilateral devices of the type studied here. (C) 2010 Acoustical Society of America. [DOI: 10.1121/1.3293002]
|Title:||Resistance to learning binaurally mismatched frequency-to-place maps: Implications for bilateral stimulation with cochlear implants|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||Copyright 2010 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America|
|Keywords:||DICHOTIC SPEECH RECOGNITION, SPECTRALLY SHIFTED SPEECH, NOISE-VOCODED SPEECH, PERCEPTUAL ADAPTATION, INSERTION DEPTH, ELECTRODE ARRAYS, ENVELOPE CUES, HEARING, NUMBER, INTELLIGIBILITY|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Psychology and Language Sciences (Division of) > Speech, Hearing and Phonetic Sciences
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
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