Changes in aerodynamic characteristics of stutterers' fluent speech associated with therapy.

Stuttering frequency and four aerodynamic measures of articulatory events within perceptually fluent voiced and voiceless intervocalic intervals were obtained from 15 stutterers prior to and at the termination of a concentrated program of stuttering therapy. Three of the four aerodynamic variables showed group changes over the course of therapy concomitant with improvements in fluency. Additional correlational analyses suggested that one of the aerodynamic variables was specifically related to stuttering frequency. It is argued that both fluency enhancing and ancillary components of therapy operate to influence the intervocalic interval.