Immediate speech fluency improvement after application of the Digital Speech Aid in stuttering patients

BACKGROUND The Digital Speech Aid (DSA) is a pocket-sized device used for speech correction in stutterers. The device modifies the patient's auditory feedback with the use of Delayed Auditory Feedback (DAF) and Frequency-shifted Auditory Feedback (FAF). Both methods are well-known to improve speech fluency in stuttering persons. The aim of this study was to assess immediate disfluency reduction after application of the DSA. MATERIAL/METHODS The study included 335 patients aged 6-64 years with speech disfluency. DSA fitting was performed during 3-day hospitalization. Speech disfluency was assessed during reading, in dialogue and in monologue before fitting and after selection of optimal DAF and FAF parameters. Fluency improvement was assessed statistically with Student's t test for logarithms of the odds of disfluency presence without the DSA and with the DSA. RESULTS For all speaking situations, statistically significant improvement was achieved, with p<0.005. Immediate fluency improvement was observed in 82.1% of patients during reading, in 84.5% during dialogue, and in 81.2% during monologue. Values different from placebo (reliable improvement) were obtained in 66.9% of patients during reading, in 66.6% during dialogue, and in 63.9% during monologue. CONCLUSIONS The results show that the DSA is an effective tool for immediate disfluency reduction in stutterers.