PROLONGED SPEECH AND MODIFICATION OF STUTTERING - PERCEPTUAL, ACOUSTIC, AND ELECTROGLOTTOGRAPHIC DATA

Prolonged speech and its variants are a group of novel speech patterns that form the basis of a popular treatment for stuttering (Ingham, 19 84). It is difficult to determine which features of prolonged speech a re necessary for the elimination of stuttered speech because the speec h pattern produces simultaneous changes in respiratory, laryngeal, and articulatory activity. Experimental studies have shown that the modif ication of phonation and of speech rate contributes to stuttering redu ction, and increased duration of speech segments and reduced variabili ty of vowel duration are known to occur as a result of prolonged-speec h treatment programs. However, previous studies of prolonged speech ha ve all instructed subjects to modify their customary speech patterns i n a particular way. The aim of the present study was to investigate ch anges in the speech pattern of individual subjects when stuttering was modified with prolonged speech without specific instruction in how th is should be done. In one experimental phase, 3 subjects showed clinic ally significant stuttering reductions when instructed to use whicheve r features of prolonged speech they needed to reduce their stuttering. The resulting perceptually stutter-free speech was judged to be natur al sounding. Stuttering in a fourth subject reduced without experiment al intervention. Recordings of acoustic and electroglottographic signa ls from the 4 subjects were analyzed. Changes in the variability of vo wel duration occurred in all subjects. Theoretical and clinical implic ations of the results are discussed.