Phonological pattern frequency and speech production in children and adults

Recent experimental and theoretical studies have suggested that both adults and children are sensitive to information about phonological pattern frequency. The majority of this evidence comes from studies of speech perception and lexical processing. The influence of phonological pattern frequency on speech production has not been studied extensively. The current study examined the effect of phonological pattern frequency on speech production by looking at two low-level aspects of articulation, fluency and flexibility. Three groups of subjects (preschool children, early school-aged children, and adults) completed a nonsense word repetition task, which was subjected to an acoustic analysis.; The mean duration of the sixteen target sequences served as a measure of fluency. ANOVA showed that infrequent diphone sequences were articulated with longer durations than frequent ones. In a second analysis, separate hierarchical multiple regressions were performed predicting diphone duration from pattern frequency for each age-group. It was found that measures of pattern frequency predicted duration for the two youngest groups of subjects but not for the adults.; Three separate analyses examined flexibility. In the first analysis, percent correct production of diphone sequences was analyzed, and it was found that children, but not adults, repeated infrequent sequences of phonemes less accurately than they repeated frequent ones. This result suggests that children are not able to maintain correct phoneme production in low-frequency contexts. In the second analysis, variability in diphone duration was examined. Analysis of variance found that phonological pattern frequency influenced variability in duration, with infrequent sequences of sounds being produced with more variable durations than frequent ones. In a third analysis, no effect of pattern frequency on spectral variability was found.; Thus, there appears to be an influence of phonological pattern frequency on lower-level aspects of articulation. Infrequent sequences are produced with longer durations, and are more variable in their duration. In addition, the effect of pattern frequency on fluency interacts with age: regression analyses find that pattern frequency influences mean diphone duration for children but not for adults.