Perceptual assessment of normalcy of speech following stuttering therapy.

Stuttering therapy procedures such as rhythmic or prolonged speech have been criticized because afterward the subject may speak fluently but also abnormally. Although assessments of the normalcy of speech behavior have been rare, some recent procedures have included perceptual assessments of certain dimensions of speech behavior. This study reports an evaluation procedure where listeners endeavored to distinguish between intermingled speech samples obtained from treated stutterers and a peer group of normally fluent speakers. Different groups of listeners were asked to judge the prosody, rate, fluency, and naturalness of posttreatment samples from a group of stutterers treated with a prolonged speech procedure, and a matched peer group of noramlly fluent speakers. No significant differences were found between the assessments of stutters and normally fluent speakers. However, when another group of listeners was asked to decide whether the speech samples were from treated stutters or normal speakers, the stutters received significantly fewer normal speaker judgements. Interrelationships between the judgment scales were evaluated along with a forced-choice procedure for assessing the normalcy of individual speech samples.