The permanent hearing loss produced by extended exposure to certain occupational noises constitutes a serious health problem. The solution to this problem lies in active programs of hearing conservation. Hearing conservation is primarily a medical responsibility. The importance of the physician's recognition of his role in meeting the threat to health cannot be overemphasized.
The physician must acquaint himself with the current knowledge of the relations of hearing loss to noise exposure. Misconceptions about the hazardous effects of noise are widespread. Auditory effects of noise exposure and nonauditory effects are frequently related without justification. For example, the fact that a noise produces annoyance does not, contrary to popular belief, mean that exposure to that noise will necessarily produce a hearing loss. The annoyance caused by noise is a highly individual phenomenon and, as such, is not easily measured or predicted. The fact that a noise produces annoyance does not mean that it is bad for health.
The total amount of hearing loss produced by noise exposure depends on more variables than was thought originally. Before the diagnosis of noise-induced hearing loss can be made the physician must have adequate information about (1) the over-all sound pressure level of the noise, (2) the way the energy in the noise is distributed among the various frequencies present, (3) the typical pattern of daily exposure to the noise, and (4) the years of expected work life in the noise. Answers given by the patient cannot be assumed to be reliable, and the physician must make the necessary effort to obtain the pertinent information from reliable sources.