THE SPECIFIC RELATION BETWEEN PERCEPTION AND PRODUCTION ERRORS FOR PLACE OF ARTICULATION DEVELOPMENTAL APRAXIA OF SPEECH

Developmental apraxia of speech is a disorder of phonological and arti culatory output processes. However, it has been suggested that percept ual deficits may contribute to the disorder. Identification and discri mination tasks offer a fine-grained assessment of central auditory and phonetic functions. Seventeen children with developmental apraxia (me an age 8:9, years:months) and 16 control children (mean age 8:0) were administered tests of identification and discrimination of resynthesiz ed and synthesized monosyllabic words differing in place-of-articulati on of the initial voiced stop consonants. The resynthetic and syntheti c words differed in the intensity of the third formant, a variable pot entially enlarging their clinical value. The results of the identifica tion task showed equal slopes for both subject groups, which indicates no phonetic processing deficit in developmental apraxia of speech. Th e hypothesized effect of the manipulation of the intensity of the thir d formant of the stimuli was not substantiated. However, the children with apraxia demonstrated poorer discrimination than the control child ren, which suggests affected auditory processing. Furthermore, analyse s of discrimination performance and articulation data per apraxic subj ect demonstrated a specific relation between the degree to which audit ory processing is affected and the frequency of place-of-articulation substitutions in production. This indicates the interdependence of per ception and production. The results also suggest that the use of perce ptual tasks has significant clinical value.