PERCEPTUAL RATING INSTRUMENT FOR SPEECH EVALUATION OF STUTTERING TREATMENT

A rating instrument is described that can be used to assess the result s of stuttering treatments. The instrument is designed for use with na ive listeners. It yields a comprehensive and detailed description of t he speech quality in terms of articulation, phonation, pitch, and loud ness; in addition, it includes a naturalness scale. Analysis of rating s obtained with the instrument show that naturalness is a multidimensi onal characteristic. Moreover, the speech characteristics that determi ne the naturalness ratings appear to be different pretreatment, posttr eatment, and at follow-up treatment. The psychometric characteristics of the instrument are analyzed in detail. It is concluded that mixing of samples of stutters and nonstutterers in one rating experiment may artificially inflate the reliability of the ratings. Also, ratings on equal-appearing interval scales cannot be interpreted in an absolute s ense. Solutions for this methodological problem are suggested.