The locus equation as an index of coarticulation in syllables produced by speakers with profound hearing loss.

Locus equations (LEs) were derived from consonant-vowel-consonant (CVC) syllables produced by four speakers with profound hearing loss. Group data indicated that LE functions obtained for the separate CVC productions initiated by /b/, /d/, and /g/ were less well-separated in acoustic space than those obtained from speakers with normal hearing. A general trend of reduced anticipatory coarticulation was obtained for contexts in which speakers with normal hearing ordinarily coarticulate. One speaker engaged more coarticulation than did speakers with normal hearing. Speakers' productions could be ordered in a way that locus functions appeared to progressively collapse upon one another, suggesting a progressive reduction of consonant separation in acoustic space. The applications of the locus equation as an index of coarticulation and intervention outcome measure are discussed.