DAF as instrumental treatment for dysarthria in progressive supranuclear palsy: a case report.

In this case study, a 59-year-old male with progressive supranuclear palsy and hypokinetic dysarthria wore a small, solid state, battery operated, delayed auditory feedback device to reduce speech rate and to aid speech intelligibility. Time series measurements were made from tape recordings taken at the beginning of treatment and again after three months of daily wearing of the device. Measures of speech rate, intensity, and overall intelligibility indicate that when the instrument is worn, the subject's speech is slowed, vocal intensity increases, and intelligibility is markedly improved. The subject and his family report satisfaction with the instrument. The application of delayed auditory feedback to the treatment of communication disorders is discussed.