Language-induced voice quality variability in bilinguals

Abstract

The paper examines whether the language spoken exerts influences on a speaker's voice quality. Bilingual (Catalan/Spanish) subjects were studied in order to neutralize the speakers individual characteristics. The Long Term Average Spectrum (LTAS) was used as an acoustical measure of voice quality. The sample of 12 males and 12 females was divided into two categories of linguistic dominance (Catalan and Spanish dominances). Each subject produced five repetitions each of a Spanish and a Catalan phonetically balanced text. A 400-line LTAS was computed for each repetition; the 240 spectra so obtained were compared by means of a pattern recognition procedure (SDDD dissimilarity index). Within-speaker comparisons of two kinds were performed: the between-language (Catalan/Spanish) and the within-language (Catalan/Catalan and Spanish/Spanish) ones. The between-language variability was higher than the within-language variability, irrespective of the sex and language dominance categories. The data, moreover, exhibited a tendency towards greater within-language variability in the dominant language than in the non-dominant one. Finally, a greater correlation in the Catalan dominant group between intra- and inter-language LTAS dissimilarities suggests differences in the mastery of the second language between the two dominance groups.