Variability in the production of words containing consonant clusters by typical two- and three-year-old children

Variability describes speech differences within individual children, as well as differences between children. Variability within children has been used as an indicator of speech impairment, so knowledge of typical children's variability enhances clinicians' diagnostic and prognostic decisions. This study aimed to describe the extent of variability within children in the production of consonant clusters. Patients and Methods: Sixteen typically developing children aged between 2 and 3 years were studied monthly for 6 months. Spontaneous speech samples were used to construct variability profiles for repeated productions of words containing consonant clusters. Results: Variability between and within individuals featured prominently. Half (53.7%, range 42.4-77.6%) of all the words that were repeated were produced variably. As the children became older, they increased the accuracy of their productions overall; however, variability between and within individuals continued to occur. Conclusion: If the speech of typically developing children is highly variable, then the extent and nature of variability must be defined when it is used as a diagnostic marker of speech impairment.