The development of oral diadochokinesia and non-linguistic rhythmic skills in normal and speech-disordered young children.

A study was made of the oral diadochokinetic rates, non-linguistic rhythmic skills and auditory sequential memory of 60 normal and 30 severely speech-disordered children aged 3-5 years. Results were analysed and the speech-disordered children showed a wide range of difficulties. All age groups of the speech-disordered children scored significantly less well than the normal children on the three tasks. Their diadochokinetic rates showed a particular problem with the sequencing of different sounds rather than with repetitions of the same sound. Their rhythmic skills showed greatest difficulty with the stress component of the task. Their auditory sequential memory was significantly poorer than the normal children. These difficulties are interpreted as a sign of a deficit of fine motor coordination and timing in the speech-disordered children. Diadochokinetic rates and non-linguistic rhythmic skills are shown to be developmentally age-related abilities in normal children.