Modification of listener-judged naturalness in the speech of stutterers.

This study investigated the effect of regular feedback of listener-judged speech naturalness ratings on the speech of stutterers. Six adult stutterers each participated in a time-series ABA experiment. During the treatment phase the stutterer was instructed to improve a clinician's rating, on a 9-point scale, of the naturalness of each 30-s interval of the stutterer's spontaneous speech. The results indicate that the naturalness ratings and stuttering for 5 of the subjects made favorable changes during the treatment phase. Analyses of the findings show that only some of the naturalness judgments were influenced by stuttering frequency and speech rate. A perceptual analysis of the speech of 2 subjects suggested that the speech naturalness ratings were also probably influenced by other less obvious variables.