Effects of a prosodic control approach for patients with motor speech disorders

Abstract

For patients with motor speech disorders, the Lee Silverman method (Ramig, 1997) has been known as an effective voice therapy method. In our clinical experiences, however, some Japanese patients could not easily produce very loud voice required in the method, presumably due to the cultural background. Therefore, in this study, a prosodic control approach called ‘‘the intonation emphasis therapy’’ was used as well as the Lee Silverman method for three types of patients. The disorder types were amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PK), and olivo-ponto-cerebellar atrophy (OPCA). Acoustic analyses revealed wider F0 ranges after the intonation emphasis therapy than the Lee Silverman method for three types of the patients. In the perceptual judgments by speech therapists regarding articulation, voice quality, intonation, and abnormal impression of speech, better ratings were obtained for the intonation emphasis therapy than for the pretherapy speech and the Lee Silverman method in the patients with ALS and PK. However, the listeners perceived inappropriate intonation and increased abnormality for the OPCA patient after the intonation emphasis therapy. It was suggested that our therapy method was effective for patients with motor speech disorders unless the disorders were associated with poor muscular coordination such as OPCA.