Excessive noise levels may permanently or temporarily damage a person's hearing. Whenever possible, employees should reduce noise levels to an acceptable level. The following table outlines OSHA limits for acceptable noise exposure indicated as decibels (dB).
| Duration/Day (Hours) | Sound Level (db) |
| 8 | 90 |
| 6 | 92 |
| 4 | 95 |
| 3 | 97 |
| 2 | 100 |
| 1½ | 102 |
| 1 | 105 |
| ½ | 110 |
| ¼ or less | 115 |
Hearing loss can be permanent - wear protective equipment when noise levels are high.
Before using personal protective equipment, such as ear plugs or muffs, to reduce noise exposure, try to reduce noise levels by changing work procedures. Maintenance practices, such as the following, can reduce noise levels:
The following table illustrates various noise levels:

dB Level Chart Select Sounds
Engineering controls, such as the following, can also reduce noise levels:
Areas that may require hearing protection include machine shops, the power plant, etc. Observe all warning signs and wear hearing protection whenever necessary. Do not interfere with, remove, or modify noise abatement equipment. Keep all equipment properly maintained, and report any malfunctions immediately.
Refer to the chapter on Personal Protective Equipment for more information on hearing protection. Direct all questions regarding hearing conservation to Risk Management & Safety Office.