Context effects in loudness have been observed in normal auditory perception and may reflect a general gain control of the auditory system. However, little is known about such effects in cochlear-implant (CI) users. Discovering whether and how CI users experience loudness context effects should help us better understand the underlying mechanisms. In the present study, we examined the effects of a long-duration (1-s) intense precursor on the loudness relations between shorter-duration (200-ms) target and comparison stimuli. The precursor and target were separated by a silent gap of 50 ms, and the target and comparison were separated by a silent gap of 2 s. For normal-hearing listeners, the stimuli were narrowband noises; for CI users, all stimuli were delivered as pulse trains directly to the implant. Significant changes in loudness were observed in normal-hearing listeners, in line with earlier studies. The CI users also experienced some loudness changes but, in contrast to the results from normal-hearing listeners, the effect did not increase with increasing level difference between precursor and target. A “dual-process” hypothesis, used to explain earlier data from normal-hearing listeners, may provide an account of the present data by assuming that one of the two mechanisms, involving “induced loudness reduction,” was absent or reduced in CI users.
|Original language||English (US)|
|Number of pages||11|
|Journal||JARO - Journal of the Association for Research in Otolaryngology|
|State||Published - Aug 3 2015|
Bibliographical noteFunding Information:
This work was supported in part by NIH grant R01 DC012262. Author NW was supported by Advanced Bionics and by a Doctoral Dissertation Fellowship from the Graduate School of the University of Minnesota.
© 2015, Association for Research in Otolaryngology.
- auditory context effects
- cochlear implants
- loudness enhancement
- loudness recalibration