Effects of segment and pause manipulations on the identification of treated stutterers

This study examined the hypothesis that reading rate affects the identification of treated stutterers. Thirty-two pairs of recorded speech samples, in which one member of the pair was a treated stutterer and the other was a nonstutterer, were available from previous research. Listeners had been able to distinguish readily between the members of these pairs. For each pair of samples, the durations of the treated stutterer's segments and pauses were adjusted to match those of the nonstutterer as closely as possible by means of a computer-based waveform editor. A test tape was prepared that included the 32 original pairs of stimuli, the 32 edited pairs, and 64 pairs of foils. Listeners were required to indicate which member of each pair was the treated stutterer. Analysis of the responses indicated that the listeners' ability to distinguish between talkers was significantly reduced for the edited stimulus pairs. The results imply that the rate used by treated stutterers must be critically evaluated if the goal of therapy is the production of perceptually "normal" speech.