Hearing Conservation

Hearing conservation programs are designed to prevent hearing loss due to noise and other environmental factors in different segments of society. Regarding occupational exposures to noise, a written hearing conservation program is required by the Occupational Safety and Health Administration (OSHA) "whenever employee noise exposures equal or exceed an 8-hour time-weighted average sound level (TWA) of 85 decibels measured on the A scale (slow response) or, equivalently, a dose of fifty percent." This 8-hour time-weighted average is known as an exposure action value. While the Mine Safety and Health Administration (MSHA) also requires a hearing conservation program, MSHA does not require a written hearing conservation program. MSHA's hearing conservation program requirement can be found in 30 CFR ยง 62.150, and requires has almost the same exact requirements as the OSHA hearing conservation program requirements.

A sound survey is often completed to determine areas of potential high noise exposure. This type of survey is normally completed using a sound level meter (SLM). There are three types of sound level meters. Type 0 is precision instrument normally used in laboratories. A type 1 is for precision measurements taken in the field. Type 2 sound level meters are less precise than type 1 and are often used to take all-purpose sound level measurements. Noise monitoring is generally completed using a noise dosimeter that integrates "all continuous, intermittent and impulsive sound levels" to determine a person's noise exposure level. Surveys must be repeated when there are significant changes in machinery and/or processes that would affect the noise level.