ABSTRACT
A central issue for many years in clinical linguistics has been the question of the status of apraxia of speech. Essentially, argument has centred on whether apraxia of speech is best seen in terms of impairment of linguistic or phonetic components of the standard generative model of the grammar. A critical examination of the research completed in recent years shows that linguistic description on its own is unable to differentiate between apraxia of speech and aphasia. Cognitive phonetics cannot actually help distinguish apraxic from dysarthric from aphasic speech. That requires a data-oriented approach as taken by studies of apraxia of speech which have employed the fluency dimension. Phonetic and phonological study has been unable to distinguish, at a segmental level, between fluent aphasia and apraxia of speech. It is in fact the suprasegmental dimension of fluency which appears to be the most important means of distinguishing between aphasic and apraxia production errors.
