Apraxia of speech in patients with Broca's aphasia: A study of phoneme production accuracy and error patterns

Phonetic analyses were made of the articulatory errors of ten Broca's aphasics with apraxia of speech. Presentation mode, phoneme position, and phoneme frequency-of-occurrence were related to phoneme difficulty. Consonant clusters were more difficult than consonant singletons; vowels were easiest. Substitution, addition, and compound errors predominated, while distortions and omissions were much less frequent. A subphonemic feature analysis of substitution and distortion errors showed a majority of errors to be close approximations to target phonemes.