Stuttering: speech pattern characteristics under fluency-inducing conditions

Speech samples were collected from three adult male stutterers under six baseline conditions and 15 conditions believed to increase fluency. After moments of stuttering and filled pauses had been deleted from the samples, a speech pause analysis technique developed by Goldman-Eisler was used to measure the following speech pattern characteristics: mean phonation duration (i.e., the duration between pauses), pause proportion, articulation rate, fluent speech rate, mean sentence length, and percentage of syllables stuttered. Greater than 50% reduction in stuttering occurred in all but three conditions (Speak and Write, Relaxed, Alone with cards). Greater than 90% reduction occurred under Prolonged/DAF speech, Singing, Chorus reading, Shadowing, Slowing, Syllable-timed speech, and Response contingent stimulation. The data were examined for evidence of speech pattern characteristic changes which were associated with reduced stuttering. Lengthened mean phonation duration occurred consistently under four conditions: Chorus reading, Shadowing, Singing, and Prolonged/DAF. Slowed speech (lower overall rate, lower articulation rate, or increased pause proportion) occurred consistently in seven conditions: Prolonged/DAF, Slowing, Syllable-timed speech, Arm swing, Speak and write, Relaxed, and Singing. Only in Prolonged/DAF speech did lengthened phonation duration occur in conjunction with slowed speech. The results of this exploratory study suggest that stuttering may be reduced under different conditions by means of different strategies. Lengthened phonation and slowing were the predominant strategies used in those conditions investigated in this study. The results are consistent with those of effective treatment techniques. Theoretical accounts of the association between change in fluency and change speech pattern characteristics are discussed.