An acoustic and perceptual study of R‐L versus L‐R coarticulation

Abstract

Coarticulation has been observed in physiological, acoustic, and perceptual investigations. However, conflicting evidence exists at each level of observation concerning the relative importance of right to left (R‐L) versus left to right (L‐R) coarticulation. Differing speech samples and research methods may account for conflicting data. To test this hypothesis, effects of R‐L and L‐R coarticulation were examined in methodologically related acoustic and perceptual factorial experiments. Eighty‐four 60‐ms vowel segments devoid of transitions were extracted from three isolated vowels, 27 ′V, CV,27 ,V′CV, and 9 CVC utterances and were examined for change in F2 of contextual [i,ɑ,u] and perceptual recovery of adjacent [p, t, k]. Listeners were 18 phonetically naive college students. No simple perceptual or acoustic advantage of one coarticulatory direction over the other was found. Instead, coarticulatory direction interacted with stress to affect consonant recovery and change in F2. This finding led to speculation that listeners may have responded to cues common to stress and consonant environment including amplitude and fundamental frequency rather than to frequency information provided by F2.