Pause distribution and working memory capacity in L2 speech production

Abstract

Departing from a cognitive account of oral speech production, the present study aimed at (1) identifying the role silent pause distribution has in defining fluency, and (2) disentangling the relationship between working memory capacity (WMC) and second language (L2) fluency. Data was gathered at the Universidade Federal de Santa Catarina, from 12 Brazilians (native speakers of Brazilian Portuguese - BP - and L2 speakers of English) and 9 Americans (native speakers of American English - AE). All participants carried out picture description and narrative tasks, orally and spontaneously, in their first languages (L1s). The Brazilian participants also performed these oral tasks in their L2 (English) and a WMC test - the L2 Speaking Span Test (L2 SST). Participants' fluency was assessed through frequency of pauses at and within clause boundaries and mean length of run (MLR). The a level was set at .05. The statistical analyses employed indicated that while the two first languages under scrutinity (AE and BP) did not differ regarding pause distribution or MLR, the L2 (English) speech of the Brazilians presented more pauses (especially within boundaries) and shorter MLRs than both their own L1 (BP) speech and the L1 (AE) speech of the Americans. Moreover, significant correlations were found between individuals' L2 SST scores and frequency of within boundary pauses and MLR. Concerning fluency, the results support the role MLR has in defining fluency and demonstrate the importance of frequency of pauses within rather than at boundaries in distinguishing less and more fluent speakers. As regards the relation between L2 fluency and L2 WMC, it seems that due to being more controlled than L1, L2 oral speech is at least in part constrained by individuals' limited attentional resources, with larger-capacity speakers being better able to sustain L2 fluency (with fewer pauses within boundaries and longer speech runs) than those speakers with fewer resources.