Combined effects of noise and hand-arm vibration on auditory organ and peripheral circulation

• Published in: Journal of sound and vibration Vol. 151; no. 3; pp. 395 - 405
• Main Authors: Miyakita, T., Miura, H., Futatsuka, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 22.12.1991
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/0022-460X(91)90536-S

This paper first presents an overview of an epidemiological study on noise-induced hearing loss (NIHL) in relation to vibration-induced white finger (VWF). Secondly, the results obtained in a model experiment with a chain-saw under laboratory conditions are discussed from the viewpoints of elucidating the etiological mechanisms of VWF and NIHL. In the epidemiological study, in which 499 chain-saw workers were examined, chain-saw workers with VWF showed a significantly greater hearing loss at high frequencies than those without VWF. Next, an experimental study was designed to determine whether a combination of noise and vibration produced more pronounced changes in temporary shifts of finger skin temperature and temporary threshold shift (TTS) of hearing than those resulting from exposure to either stress alone. The results suggested that noise might play a part in inducing the constriction of the peripheral vessels seen with local exposure to vibration, and that hand-arm vibration may produce an additive effect on the noise-induced TTS. Furthermore, finger skin temperature and finger blood flow were measured simultaneously as indicators of peripheral circulatory movement for five healthy subjects. The relation between the synergistic action of noise and vibration and the participation of the sympathetic nervous system are also discussed.