The perception of foreign accent in prosody-transplanted speech

This study investigates the contribution of prosody to Korean native listeners’ perception of foreign accent in Chinese-accented Korean speech. Unlike many previous studies, the current work examined synthesized speech where L2 talkers’ production of prosody was transplanted onto L1 talkers’ segments, and vice versa. This experimental technique allowed for observing a separate and individual role of prosody while both segmental and prosodic information was preserved as in natural utterances. This work first investigates the relative weight of segments and prosody and then narrows down the scope to prosody alone. In the experiment, the stimuli for foreign accent perception was prepared in such a way that prosodic information was cross-planted onto segmental representations between L1 and L2 Korean speech. A group of fifteen Korean native listeners rated foreign accent, and the results show that the stimuli with combined L2 prosody and L1 segments were rated as less accented than those of L1 prosody and L2 segments. This suggests that segments played a more influential role than prosody in the perception of foreign accent. In the results of individual/independent roles of prosodic parameters such as duration, pitch and intensity, duration turned out to make a more prominent contribution to Korean listeners’ detection of foreign accent. That is, Korean listeners are more likely to rely on the temporal aspects of speech because the consonants/vowels were reset in the temporal dimension once duration was transplanted. This is an extended finding of Lee and Liu (2012), Liu and Lee (2012), and Lee (2014) that the matter of which prosodic parameter contributes more to foreign accent is substantially L1-specific, reflecting the prosodic structure of the L1.