Andrew Stuart & Joseph Kalinowski

The design and operating characteristics of the first self-contained in-the-ear device incorporating a micro-digital signal processor capable of delivering altered auditory feedback (AAF) for persons who stutter (PWS) was recently described (Stuart et al., 2003). Evidence from our laboratory supports the contention that this device may be a therapeutic alternative or adjunct to present therapy options: The proportion of stuttering during reading and monologue at 12 months post fitting was significantly reduced relative to pre-fitting. Self-report of behaviour related to struggle, avoidance and expectancy was significantly reduced at 12 months following initial fitting. The naturalness of speech produced by users while reading and during monologue with the device was rated by naïve listeners as more natural sounding than produced by users without the device. Additional data also supports the contention that not only can AAF reduce stuttering episodes for PWS, the duration of the residual stuttering is also significantly reduced as well as the total amount of time stuttering. No differential effect on the reduction of proportion of stuttering type (i.e., prolongation, repetition, or silent block) was evidenced with AAF. The observation that AAF does not have a differential effect on stuttering type was surprising. It was our initial clinical impression that those individuals who have stuttering predominately characterized by silent blocks were less likely to benefit from AAF. That is, it was our opinion that when one is "locked" in a silent block there is no auditory alteration in their speech signal to "push" them through their stuttering episode. It appears that this is not the case and it does not appear to explain the individual variation in responsiveness to AAF.