A phonological investigation of four siblings with childhood autism.

Multiple autistic siblings of four or more are extremely rare. This study carried out a phonological investigation of four siblings in a unique family. Phonological investigations were carried out on four siblings with childhood autism (one female and three males). In addition, behavioral characteristics were described and compared among the four children. The two methods used for speech elicitation were object naming and spontaneous speech utterances. Data analyses included phonetic inventory and phonological process analyses. Phonological investigations showed that these autistic children, at least the more severely impaired ones, do not only exhibit delayed phonological behavior, but also show some atypical patterns that rarely occur in normal development. Findings from this study reveal five general patterns of phonological behavior, namely: (a) evidence of several phonological processes that are common in normal development; (b) persistence of several phonological processes, such as labialization, cluster reduction, or final consonant deletion, beyond the expected age; (c) evidence of unusual sound changes, such as extensive segment coalescence, frication of liquids, and velarization; (d) evidence of "chronological mismatch" (Grunwell, 1981), which is the notion of the absence of earlier sounds co-occurring with characteristics of later development; and (e) restricted use of contrasts. These findings support earlier work on a single autistic child using phonological investigations (Wolk & Edwards, 1993), but contrast with all previous research suggesting that autistic children exhibit delayed rather than unusual phonological development. Clinical implications are suggested.