The interaction of ambient frequency and feature complexity in the diphthong errors of children with phonological disorders

Abstract

This study examined the interaction of ambient frequency and feature complexity in the diphthong errors produced by Cantonese-speaking children with phonological disorders. A total of 611 diphthongs produced by 13 Cantonese-speaking children with speech disorders were subjected to perceptual analysis. The percentage accuracy of production and error patterns was examined. Perceptual analysis showed that /oi/ and /ui/ were most frequently in error, whereas /ei/, /ou/, and /au/ were least frequently in error. Diphthong errors (usually diphthong reduction) arise as a function of both ambient frequency and feature complexity. The combination of ambient frequency and feature complexity yields a complexity metric reflecting accuracy of production. Treatment guidelines include consideration of three basic factors: ambient frequency, feature complexity, and error patterns.