Exploring the Onset of Phonetic Drift in Voice Onset Time Perception

Abstract

Recent exposure to a second or foreign language (FL) can influence production and/or perception in the first language (L1), a phenomenon referred to as phonetic drift. The smallest amount of FL exposure shown to effect drift in perception is 1.5 h. The present study examined L1 perception at earlier timepoints of FL exposure, to determine whether the phonetic system is able to resist FL influence at an incipient stage. In a longitudinal pre-test/post-test design, L1 English listeners were exposed to Tagalog under different conditions varying in attention directed to the voice onset time (VOT) plosive contrast in the FL; they then completed an identification task on L1 tokens from VOT continua. In every condition, the likelihood of “voiceless” identifications decreased. This change indicates a shift towards a longer VOT crossover point between “voiced” and “voiceless”, consistent with dissimilatory drift in perception. Listeners in a control condition, however, displayed a similar, albeit less lasting, change in L1 judgments, suggesting that the change arose partly from a task effect. We conclude by discussing directions for future research on phonetic drift in perception.