A VOT ANALYSIS OF APRAXIC APHASIC VOICING ERRORS/

The primary purpose of this investigation was to perform a VOT analysi s of correct and incorrect productions elicited from an apraxic/aphasi c speaker (S1), who consistently devoiced stop and affricate targets. A secondary objective was to analyse the VOTs of an apraxic/aphasic sp eaker (S2) who produced stop and affricate voicing distinctions correc tly, as determined by broad phonetic transcription. Seven hundred and ninety monosyllabic words, representing four voiced-voiceless cognate pairs, were analysed for each subject. VOT results indicated that S1's error productions (i.e. [t] for /d/; [p] for /b/; [k] for /g/; and [t integral] for /d(3)/) differed significantly from his correct, voicel ess, homonymous productions (i.e. [t] for /t/; [p] for /p/; [k] for /k /; and [t integral] for /tf/). Therefore, Si's sound errors were not c onsidered to be sound substitutions, as had been indicated perceptuall y. Overlapping VOT values were found for all of S2's voiced-voiceless cognate pairs, despite perceptually accurate productions, indicating p ossible speech motor control problems.