Temporal variables in first and second language speech and perception of fluency

Evidence is accumulating that many temporal features of second language speech are correlated with those of first language speech. This study looks at the correlation between articulation rate, pause rate, and mean pause duration in Japanese first and English second language speech and how second language fluency raters perceive these. In a crosslinguistic corpus of spontaneous speech, mean pause duration was found to have a near-high correlation while the other two temporal variables have a moderate correlation. A subsequent elicitation of fluency judgments on the second language English speech via Amazon Mechanical Turk showed that ratings were highly dependent on pause duration, rather less on articulation rate, but not on pause rate. Results suggest that raters’ perception of second language fluency is divergent from speakers’ actual second language development: Ratings are related to features that are not indicative of second language development but rather of individual speech patterns.