The effect of portable DAF usage in daily life on the speech intelligibility of dysarthrias

Abstract

Dysarthria is a neurologic motor speech impairment due to a pathological change of nerve and muscle system. Several rehabilitation methods of speaking rate control have been widely used to improve speech intelligibility for mild dysarthria. Nevertheless, speech intelligibility of the dysarthric patients show almost no improvement outside of a clinic. Delayed auditory feedback(DAF)is one of the speaking rate control methods. Recently a small portable DAF device has been developed, which enables dysarthric patients to use it in their daily life. In this study, wearing a portable DAF, two dysarthric patients conducted a 20-minute practice per day for three months. In the practice, they instructed to prolong vowel length in DAF usage. Intelligibility tests for single-word utterance and for reading aloud a long sentence were conducted before and after the practices. As a result, the single-word intelligibility score increased from 84.0% to 90.6% in case1, and from 68.3% to 89.7% in case2. Additionally, vowel space in the F1-F2 space in case2 enlarged. Both the performance of long sentence reading and free conversation will be presented in the meeting. These results suggest that a portable DAF effectiveness in daily use. This work was supported by JSPS KAKENHI 10424889.