Measuring speech motor skills in phonologically disordered pre-school children and their normally developing peers.
Previous research has demonstrated that normally developing children are expected to have
adult like control of their speech production skills by 10 years of age, as evidenced by
increases in speed of production and decreases in performance variability. (e. g. Kent and
Fortier 1980). There is also some evidence to suggest that phonologically disordered
children may have poorer speech motor skills than their normally developing peers (e. g.
Henry 1990, Edwards 1992, Waters 1992, Towne 1994).
There are numerous techniques that can be used to measure a number of different aspects
of speech motor control. However, there are methodological difficulties in devising
appropriate protocols for the collection and analysis of speed of speech production as used
as an index of speech motor skill in young children.
Some of the techniques that have had clinical application include measurement of rate in
connected speech production and measurement of diadochokinetic (DDK) repetition rate.
This investigation compared normally developing and phonologically disordered preschool
children on various indirect measures of speech motor skills, in imitated and
spontaneous connected speech and in DDK tasks. The investigation also focused on
refining the techniques of data collection and analysis appropriate to young children.
While the results vary with regard to the statistical significance of the differences between
the two groups of children on articulation rates and DDK rates, analysis of the error
patterns in single word, spontaneous connected speech, imitated connected speech and
DDK productions identified a sub group of phonologically disordered children who may
present with an underlying speech motor deficit as the basis of their phonological
The results of the investigation are considered in terms of their implication for the speech
motor skills of the two groups of children, techniques for measuring various aspects of
speech motor skill and the clinical identification of phonologically disordered children who
have an underlying speech motor deficit