Error-revision in the spontaneous speech of apraxic speakers.

Spontaneous speech samples from four men diagnosed with apraxia of speech were transcribed to examine the ways in which they attempted to repair their speech errors. The study sought evidence for the presence of production or perceptual constraints in error revision and for the presence of a functional prearticulatory monitor. Three judges independently evaluated the transcriptions and audiotapes to identify instances in which speakers revised speech errors. They then coded the nature of the relationship between the error and the revision. In previous reports, the form of error repairs among normal speakers has been attributed to perceptual constraints, that is, determined by the needs of the listener. Results of the present study suggest that the form of some error repairs among these speakers with apraxia of speech is not in the service of the listener; rather, it conforms with production constraints. It may be argued that some forms of error repair evidenced by these speakers, such as the prosodic marking of phonetic errors and prosodic marking in the temporal domain (syllable segregation), may actually serve to exacerbate the listener's task of message decoding. In addition, these speakers offered little evidence of an efficient prearticulatory monitor. The time delays between interrupting the flow of speech in recognition of an error and the initiation of a revision suggest an impaired ability to plan revisions prior to the production of the error.