Cerebral Dominancy Towards Various Sounds in Stutterers

• Published in: AUDIOLOGY JAPAN Vol. 13; no. 1; pp. 66 - 78
• Main Authors: Moriyama, Haruyuki, Tsunoda, Tadanobu
• Format: Journal Article
• Language: English
• Published: Japan Audiological Society 1970
• ISSN: 0303-8106; 1883-7301; 1883-7301
• DOI: 10.4295/audiology.13.66

Objective testing method available for the orientation of the dominant cerebral hemisphere towards vowel and nonverbal sounds (Tsunoda: Ind. J. Otol. 18, 78, 1966) was applied to 57 adults stutterers in order to detect the possible existence of unusual brain mechanism in speech perception. The test is binaural competing method using DAF effect performed by key tapping. All of the subjects were right handed and had not been diagnosed as having other neurological diseases. The patterns of the cerebral dominancy in stutterers thus obtained were compared with the normal standard (Tsunoda: Practica otologica Kyoto, 61 supp, 1296, 1968) and following results were obtained. 1) The normal pattern (right ear is dominant for vowel sound, while left ear far 1kHz pure tone) was found 38.6 per cent in stutterers, whereas 83.9 per cent in normals. The contra-pattern (left ear is dominant for vowel sound, while right ear for 1kHz pure tone) was found 29.6 per cent in stutterers, whereas 8.1 per cent in normals. The abnormal pattern that had been usually observed in unilateral brain damage as aphasics were found 25 per cent in stutterers, whereas 2 per cent in normals. 2) Hearing loss more than 15dB was found in 52.6 persent of stutterers especially in 4kHz and 8kHz, and 33.3 per sent of them were perceptive types. 3) The causes of most of stutterers are not clearly identified, however, the possible existence of the minimum brain damage is considered to exist in certain type of stutterers.