Noise and Hearing

Noise, or unwanted sound, is one of the most common health problems in American workplaces. The National Institute for Occupational Safety and Health (NIOSH) estimates that 30 million workers in the U.S. are exposed to hazardous noise. Exposure to high levels of noise may cause hearing loss, create physical and psychological stress, reduce productivity, interfere with communication, and contribute to accidents and injuries by making it difficult to hear warning signals. 

OSHA requires employers to determine if workers are exposed to excessive noise in the workplace. If so, the employers must implement feasible engineering or administrative controls to eliminate or reduce hazardous levels of noise. Where controls are not sufficient, employers must implement an effective hearing conservation program.

Effects of Excessive Exposure

Although noise-induced hearing loss is one of the most common occupational illnesses, it is often ignored because there are no visible effects, it usually develops over a long period of time, and, except in very rare cases, there is no pain. What does occur is a progressive loss of communication, socialization, and responsiveness to the environment. In its early stages (when hearing loss is above 2,000 Hertz (Hz)) it affects the ability to understand or discriminate speech. As it progresses to the lower frequencies, it begins to affect the ability to hear sounds in general. 

The three main types of hearing loss are conductive, sensorineural, or a combination of the two. 

The effects of noise can be simplified into three general categories:

  • Primary Effects, which includes noise-induced temporary threshold shift, noise-induced permanent threshold shift, acoustic trauma, and tinnitus.
  • Effects on Communication and Performance, which may include isolation, annoyance, difficulty concentrating, absenteeism, and accidents.
  • Other Effects, which may include stress, muscle tension, ulcers, increased blood pressure, and hypertension.
    • In some cases, the effects of hearing loss may be classified by cause.

Source http://www.osha.gov/dts/osta/otm/noise/health_effects/index.html