Consonant lingual-palatal contacts produced by normal-hearing and hearing-impaired children

Ten normal hearing (NH) and 18 profoundly hearing-impaired (HI) children were recorded using palatometry and audiotape while producing the consonants /t,d,k,g,s,z,integral of/ in CV syllables (V = /i, a/). The lingual-palatal contacts produced by the NH subjects for the alveolar stops were undifferentiated across voicing and vowel environment differences. Lingual-palatal contact patterns for the velar stops differed for vowel environment but not for voicing. The /s/ and /z/ sibilants were distinguished by groove width but not anterior place. Groove locations for /s/ and /z/ were more anterior than groove locations for /integral of/. The anterior grove location for the /integral of/ was vowel dependent. The HI subjects produced idiosyncratic lingual-palatal contact patterns. As patterns for individuals became more unique and less variable across the syllable stimuli, listener identifications showed correspondingly incorrect, undifferentiated responses. The atypical contact patterns used by the HI subjects often required interpretation of possible tongue activities during attempts at the various consonants.