Hearing Impairment Study to Stimulate Management Support for a Hearing Conservation Program

Abstract

The purpose of this study was twofold: 1) to focus both management and employee attention toward hearing impairment as a serious problem, and 2) to deliberately and systematically motivate management to institute a hearing conservation program (HCP). The study included preworkshift and postworkshift audiometric tests performed on 152 male textile plant workers exposed to daily noise levels averaging 97.4 dB(A) without hearing protection of any kind. The average hearing threshold for separate age groups was used to evaluate hearing trends. The mean hearing level of three frequencies—0.5, 1, and 2 kHz—was chosen as an index of hearing impairment, with the beginning handicap set at 25 dB hearing loss. Each employee responded to a Social Communication Ability questionnaire. Educational materials and a set of thought-provoking questions were used to stimulate management's interest in accepting hearing impairment as a real threat to employees' productivity and quality of life. The average of combined temporary and permanent threshold shift was in the range of 28 to 31 dB, showing a hearing handicap for the workers as a whole after a daily workshift. The hearing handicap interfered with the workers' everyday living to varying degrees by reducing their ability to communicate with others in society. Overall results provided tangible evidence of the noise problem in the plant. As a consequence, the company hired a part-time industrial hygienist and outlined a policy on a continuing HCP. In addition, a detailed noise survey was performed, and various measures for controlling noise exposure were considered. The implementation of a noise-reduction plan that would decrease the noise to an acceptable level was not deemed feasible; therefore, the hearing protectors became the main control method in the plant. Finally, regular audiometric testing and training programs were instituted for both management and employees. In conclusion, a hearing impairment study as described herein can be used to demonstrate the adverse impact of excessive noise exposure and to persuade management to initiate and support an HCP.