Document LJkqOwO5oZGm3Q7vGgM3ZBJz3

Fic 40-3b --Senson-neural heanng losses of the type produced by noise or other causes Curve 1--early, curve 2--intermediate, curve 3--advanced (as shown, this curve might include some involvement of presbycusis) consideration when evaluating the effects of in dustrial noise on man Management personnel can make them selves more aware of the significance of these non-noise-mduced heanng losses by establish ing a regular program of preplacement audi ometry This program will inform them of the heanng status of the individual at the time he is assigned to a job m which he may be exposed to industrial noise under conditions that could induce hearing impairment Industrial Noise Exposure As man moves through his industnal, home, and recreational environments, he is exposed to many noise sources He may be exposed to car or other transpoi tation noise during the day He may be exposed to different noises where he works He may be exposed at home to noises from radios, or a home work shop Jet planes or construction in the vi cinity of the home may be considered, in some cases, a noise exposure Thus, it can be seen that man m his many environments is exposed to different noises having vaned frequencies and intensities Noise is considered synonymous with in dustry m general and with certain specific mdustues in particular A noise survey in 1953 of 600 typical industrial operations indi cated that 75 percent of the measurements ex ceeded 90 decibels overall--on the "C" scale For a number of years, this noise level was used by some organizations as the level that should not be exceeded for heanng conserva tion Noise measurement The purpose of making noise measurements is to evaluate exposures m relation to speech interfeience, comfort or hearing loss, and to collect information for use m control The measurement of noise may be ac complished with a sound level meter, or a sound level meter in combination with an 1247