Magnitude estimation of disfluency by stutterers and nonstutterers

Everyone produces disfluencies when they speak spontaneously. However, whereas most disfluencies pass unnoticed, the repetitions, blocks and prolongations produced by stutterers can have a severely disruptive effect on communication. The causes of stuttering have proven hard to pin down - researchers differ widely in their views on the cognitive mechanisms that underlie it. The present chapter presents initial research which supports a view (Vasic and Wijnen, this volume) that places the emphasis firmly on the self-monitoring system, suggesting that stuttering may be a consequence of over-sensitivity to the types of minor speech error that we all make. Our study also allows us to ask whether the speech of people who stutter is perceived as qualitatively different from that of nonstutterers, when it is fluent and when it contains similar types of minor disfluencies. Our results suggest that for closely matched, naturally occurring segments of speech, listeners rate the speech of stutterers as more disfluent than that of nonstutterers.