Phonetic properties of aphasic-apraxic speech: A modified narrow transcription analysis

We used a modified narrow phonetic transcription procedure to examine a spe ech sample produced by 10 speakers with coexisting aphasia and apraxia of s peech. The transcription protocol was limited to eight diacritic marks sele cted based on previous perceptual descriptions of phonetic distortion among speakers with pure apraxia of speech. Additionally, there was one general distortion category for perceived distortions not captured by the main diac ritic marks. The results showed that distortion errors were as common as su bstitution errors, that vowel and consonant segments were equally vulnerabl e to misproduction, and that there was no difference between the frequency of consonants produced incorrectly in prevocalic and postvocalic syllable p ositions. Among distortion errors, 32% were classified as segment prolongat ions and 41% were classified as general distortions. An independent transcr iption that used a comprehensive system of diacritic marks was performed as a follow-up. Most general distortions were not further specified by the co mprehensive transcription system. A phonetic contrast analysis of errors de tected at the broad transcription level yielded different speech characteri stics from the observed distortion errors, but were in general corresponden ce with previously reported error patterns in intelligibility testing of th e same speech sample. The results are discussed relative to the role of sin gle word intelligibility testing in aphasia and apraxia of speech assessmen t and the challenges associated with transcribing disordered speech.