The influence of talker and accent variability on spoken word identification and discrimination

Abstract

In spoken word identification and memory tasks, stimulus variability from numerous sources impairs performance. The phonetic-relevance hypothesis (Sommers etal., 2006) proposes that only acoustic properties that influence phonetic perception (e.g., speaking rate) cause decrements in perception. In the current study, the influence of foreign-accent variability on identification and discrimination of spoken words was evaluated. In experiment 1, word identification in noise was tested in single-talker and two multiple-talker conditions: multiple talkers with the same accent or multiple talkers with different accents. In experiment 2, participants discriminated minimal pairs from a single talker, different talkers with the same accent, and talkers with different accents. Identification and discrimination performance was the highest in the single-talker conditions, but there was no difference between the single-accent and multiple-accent conditions. However, reaction time in the discrimination task was the highest in the multiple accent condition with no difference between the single-talker and single-accent conditions. Thus, the presence of multiple accents does not decrease accuracy beyond the multiple-talker effect, but processing time increases with the addition of multiple accents. These results provide partial support for the phonetic-relevance hypothesis. [Work supported by NIDCD R21DC010027 and Indiana University.]