Health hazards from noise arise primarily from sources associated with manufacturing, transportation, and recreation or entertainment. However, any noise loud enough to interfere with conversation has the potential to cause hearing loss. The three general classes of occupational noise exposure are continuous noise, intermittent noise, and impact noise. An example of continuous noise might be a piece of machinery that runs constantly. An occasional passing vehicle could be an intermittent noise, while an impact noise might come from a gunshot, explosion, or other sharp sound. Noise-induced hearing loss is a very slow, gradual process that often goes unnoticed, and usually affects both ears equally. The effects of the hearing loss are initially in the high frequency range. If exposure continues, the person is unable to hear soft sounds, or distinguish between the various sounds of speech. Hearing aids can be beneficial in some cases of noise-induced hearing loss, but prevention is the major goal. The federal government has set limits on noise exposure in the work place. If businesses exceed these limits, they’re required to have a hearing conservation program that includes frequent hearing tests, and hearing protection devices such as ear plugs and ear muffs. For more information, consult a health care provider.