Adaptation to foreign-accented speech with decreased spectral resolution

Abstract

Listening to foreign-accented speech requires greater effort, and intelligibility is lower than for native speech. We have recently shown that speech processed by a vocoder to simulate reduced spectral resolution imposes a substantial additional cost to intelligibility. The present study investigated perceptual adaptation to foreign-accented speech in conditions with reduced spectral resolution using a 9-channel tone vocoder compared to unprocessed speech. Preliminary results suggest that listeners can quickly adapt to foreign-accented speech with decreased spectral resolution. Native American English listeners achieved performance levels similar to those obtained with initial exposure to the same unprocessed speech from multiple talkers of Mandarin-accented English. However, with increased exposure, performance did not improve to the same degree found for unprocessed foreign-accented speech. Results indicate that the adaptation process is negatively impacted by the interaction of foreign accent and reduced spectral resolution, and suggests that special consideration should be given to the difficulties experienced by listeners with cochlear implants (whose devices provide limited spectral resolution) when they communicate with speakers who have a foreign accent.