Speaker variability in the coarticulation of /a, i, u/

Speaker variability in the coarticulation of the vowels / a , i , u / was investigated in / C iVC 2^ / pseudo-words, containing the consonants /p . t .k .d ^ n M .r / . These words were read out in isolation by fifteen male speakers of Dutch. The formants F |_3 (in Bark) were extracted from the steady-state of each vowel / a j , u / . Coarticulation in each of 1200 realisations per vowel was measured in F t_3 as a function of consonantal context, using a score-model based measure called CO ART. The largest amount of coarticulation was found in / u / where nasals and alveolars in exposition had the largest effect on the formant positions, especially on F2. Coarticulation in / a , u / proved to be speaker-specific. For these vowels the speaker variability of CO ART in a context was larger, generally, if CO ART itself was larger. Studied in a speaker identification task, finally, COART improved identification results only when three conditions were combined: (a) if COART was used as an additional parameter to F j_3; (b) if the COART-vaïues for the vowel were high; (c) if all vowel contexts were pooled in the analysis. The two main conclusions from this study are that coarticulation cannot be investigated speaker-independently and that COART can be contributive to speaker identification, but only in very restricted conditions.