The aim of the present study was to analyze the role of linguistic variables in the occurrence of substitution processes in the speech of subjects with verbal dyspraxia (VD). Therefore, it was carried out the phonological analysis of the speech of seven subjects with ages ranging from 2:6 (years:months) to 4:2 and diagnostic hypothesis of VD. The occurrences of usual and idiosyncratic substitution processes, assimilations and articulatory variability were statistically analyzed using the computational package VARBRUL. The variable word length was statistically significant for the occurrence of assimilations and unusual substitutions, indicating that trisyllabic and polysyllabic variants favored the highest occurrence of a process. Stress was statistically significant for the occurrence of articulatory variability and usual substitutions, showing that a process had higher probability of occurring in tonic and post-tonic syllables (syllables within the metrical foot of the accent), respectively. The class of sounds was significant for the use of usual substitutions by the subjects studied, occurring when the segments are liquid and fricative phonemes. Finally, the syllabic structure was statistically significant for idiosyncratic substitutions. The positions of final coda and simple medial onset were the most susceptible to the occurrence of a substitution process. The data of this study suggest that substitutions, in general, tend to occur in words with more than two syllables, in liquid and fricative targets, within the metrical foot of the accent (in post-tonic and tonic syllables), in simple medial onset and final coda positions.
Apraxias; Speech disorders; Speech production measurement; Phonetics; Child language; Case reports
