P. Mccabe et al., FEATURES OF DEVELOPMENTAL DYSPRAXIA IN THE GENERAL SPEECH-IMPAIRED POPULATION, Clinical linguistics & phonetics, 12(2), 1998, pp. 105-126
A typical clinical population with speech impairment was investigated
to determine the extent of the presence of features of developmental d
yspraxia and its interaction between the severity of impairment. Thirt
y diagnostic features of developmental dyspraxia were identified from
the post-1981 literature and two scales of severity were devised. Firs
t the severity of these 30 features was measured (feature severity rat
ing, FSR), and secondly severity of speech impairment was based on per
centage of consonants correct (PCC). Using these features and severity
ratings a retrospective file audit was conducted of 50 paediatric cli
ents aged 2-8 years with impaired articulation or phonology. It was fo
und that many characteristics regarded as diagnostic for developmental
dyspraxia occur in the general speech-impaired population. The relati
onship between the variables was analysed, and support was found for t
he hypotheses that: (a) there is a relationship between the number of
dyspraxic features expressed and the severity of impairment of speech
production and (b) developmental dyspraxia is not characterized by sev
ere impairment, but may occur in a range of severities from mild to se
vere.