Environmental Health and Safety

Safety Programs > Noise and Hearing Conservation


Noise and Hearing Conservation


Noise can be irritating and even cause stress and headaches. However, those conditions are temporary. Noise can also cause hearing loss, which is permanent.

Noise is measured in decibels. OSHA and PESH regulate noise above an 85 decibel level dbA (based on an 8-hour Time Weighted Average).

Noise is a significant health hazard present in many workplaces today. Prolonged exposure to noise at home or in the workplace can cause permanent hearing loss. When noise levels in the workplace exceed permissible limits established by the Occupational Safety and Health Administration (OSHA), measures such as engineering controls and hearing conservation programs are instituted to protect personnel, lowering noise levels by as much as 20-40 decibels. If you suspect elevated noise levels are present in your work area, contact EH&S at 3310 to conduct a noise level survey. If tasks expose you to noise levels high enough for the hearing conservation program, we will guide you through requirements for initial and annual hearing tests, hearing protection device selection and workplace noise analysis. When employees of the campus are involved in activities or work with equipment producing noise above the regulated threshold 85 dbA for eight hours or greater , they become subject to the requirements of the Hearing Conservation Program.

Sound is measured in units called decibels. On the decibel scale, an increase of 10 means that a sound is 10 times more intense, or powerful. To your ears, it sounds twice as loud. The humming of a refrigerator is 45 decibels, normal conversation is approximately 60 decibels, and the noise from heavy city traffic can reach 85 decibels. Sources of noise that can cause hearing loss include motorcycles, firecrackers, and small firearms, all emitting sounds from 120 to 150 decibels. Long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the time period before hearing loss can occur. Sounds of less than 80 decibels, even after long exposure, are unlikely to cause hearing loss.

Although being aware of decibel levels is an important factor in protecting one’s hearing, distance from the source of the sound and duration of exposure to the sound are equally important. A good rule of thumb is to avoid noises that are “too loud” and “too close” or that last “too long.”

Exposure to harmful sounds causes damage to the hair cells as well as the auditory, or hearing, nerve (see figure). Impulse sound can result in immediate hearing loss that may be permanent. This kind of hearing loss may be accompanied by tinnitus—a ringing, buzzing, or roaring in the ears or head—which may subside over time. Hearing loss and tinnitus may be experienced in one or both ears, and tinnitus may continue constantly or occasionally throughout a lifetime.

Continuous exposure to loud noise (> 85dbA)  also can damage the structure of hair cells, resulting in hearing loss and tinnitus, although the process occurs more gradually than for impulse noise.
Exposure to impulse and continuous noise may cause only a temporary hearing loss. If a person regains hearing, the temporary hearing loss is called a temporary threshold shift. The temporary threshold shift largely disappears 16 to 48 hours after exposure to loud noise. You can prevent Hearing Loss from both impulse and continuous noise by regularly using hearing protectors such as earplugs or earmuffs.


 Ear Plugs

Fitting Instructions for Disposable Earplugs
  • Before fitting any earplugs, make sure your hands are clean.
  • Hold the earplug between your thumb and forefinger. Roll and compress the entire earplug to a small, crease-free cylinder. While still rolling, use your other hand to reach over your head and pull up and back on your outer ear. This straightens the ear canal, making way for a snug fit.

  • Insert the earplug and hold for 20 to 30 seconds. This allows the earplug to expand and fill your ear canal.
  • Test the fit. In a noisy environment, and with earplugs inserted, cup both hands over your ears and release. You should not notice a significant difference in the noise level. If the noise seems to lessen when your hands are cupped over your ears, your earplugs are probably not fitted properly. Remove and refit following instructions

  • Always remove earplugs slowly, twisting them to break the seal. If you remove them too quickly, you could damage your ear drum.

Foam earplugs are disposable and not intended for re-use.


Contact Information

Kyle Mungavin, Director
Service Building room 217