Rhythmic typology and variation in first and second languages
This paper explores the concept of linguistic rhythm classes through a series of studies exploiting metrics designed to quantify speech rhythm. We compared the rhythm of ‘syllable-timed’ French and Spanish with that of ‘stress-timed’ Dutch and English, finding that rate-normalised metrics of vocalic interval variability (VarcoV and nPVI-V), together with a measure of the balance of vocalic and intervocalic intervals (%V), were the most discriminant between the two rhythm groups. The same metrics were also informative about the adaptation of speakers to rhythmically-similar (Dutch and English) or rhythmically-distinct (Spanish and English) second languages, and showed evidence of rhythmic gradience within accents of British English. Patterns of scores in all studies support the notion that rhythmic typology is not strictly categorical. A perceptual study found VarcoV to be the strongest predictor of the rating of a second language speaker’s accent as native or non-native.