Workers' health care of the Matsushita Electric Industrial Company is administrated by Matsushita Health Administration Center and the health administration sections are founded in all factories.
The Division of Industrial Hygiene, which is a part of the administration center, has many businesses included periodical audiometric testing of all employees exposed to noise and management of workers with hearing disorder.
The data of 12 factories indicated that percentagee of workers exposed to noise in plant is different from 0.8% to 29.2%. In the exposed groups 2.5% to 40% showed changes in hearing thresholdss at 4kHz and 2kHz. Hearing loss would become evident after more prolonged noise exposure and the elevation of threshold is aggravated by the increased magnitude of exposed noise.
The countermesures of hearing conservation from noise are restricted by various factors, but in programs, periodical hearing test is more free from the restriction. Hearing test is efffctive to the prevention, detection and management of hearing impairment.