Dept. Otolaryngol., Univ. of Tokyo, Tokyo 113, Japan
Univ. of Tokyo, Tokyo 113, Japan
Kitazato Univ., Sagamihara 228, Japan
This study was undertaken to clarify the major characteristics of voices of the Japanese-speaking patients of the adductor spasmodic dysphonia. The mechanism of the tremulous voice was also studied. For Japanese-speaking patients, to make a proper diagnosis of adductor spasmodic dysphonia, an evaluation method of the grade of the disease is needed. Sound spectrographic analysis was applied. First, the voices of the adductor spasmodic dysphonia patients were compared with the voices of other tremulous voice disease patients. Second, the voices of the different stages of adductor spasmodic dysphonia were analyzed. In the first study, results revealed that adductor spasmodic dysphonia voices showed irregularity of the fluctuation frequency in both pitch and intensity, while the voices with essential voice tremor showed a periodic fluctuation in pitch and intensity. In the second study, it was indicated that the cessation and fine flutter of the voice have a major role in the grade of the disease. With those results, phonological measurement and clinical feature can be matched. By evaluation of the irregularity of the voice, the diagnosis of tremulous voices might be confirmed. It was suggested that contributing factors to the voice symptom were not uniform.