Influence of familiarity on identifying prosodic vocalizations produced by children with severe dysarthria

Familiarity is thought to aid listeners in decoding disordered speech; however, as the speech signal degrades, the "familiarity advantage" becomes less beneficial. Despite highly unintelligible speech sound production, many children with dysarthria vocalize when interacting with familiar caregivers. Perhaps listeners can understand these vocalizations by cuing into prosodic consistencies in their child's productions. This paper examined whether familiarity influenced the identification of sustained vowels that varied in pitch, duration, and pitch-duration combinations, produced by 3 children with severe dysarthria due to cerebral palsy. Thirty-six listeners participated in the study. For each speaker, there were 2 familiar listeners (FAM), 5 experienced listeners (EXP), and 5 unfamiliar/inexperienced listeners (INX). Results indicated that familiarity did not impact identification of prosodic contrasts. In fact, all 3 listener groups were highly accurate in identifying duration, somewhat less successful at identifying pitch, and least accurate in identifying combinations of pitch and duration. Influences of speaker-listener variables on familiarity are discussed.