Noise Exposure Limits
The amount of hearing loss is dependent on the noise level and duration. Based on this a number of limits were set out in 1970 by the Ocupational Safety and Health Act for companies working for the US government.
| Limiting Daily Exposure Time [hours] | Sound Pressure Level [dB(A)] |
| 8 | 90 |
| 6 | 92 |
| 4 | 95 |
| 3 | 97 |
| 2 | 100 |
| 1.5 | 102 |
| 1 | 105 |
| 0.5 | 110 |
| <0.25 | 115 |
It should be noted that these limits were designed to protect only 85% of those exposed, with financial compensation for the rest.
A set of suggested daily noise exposure limits for nonoccupational noise are:
| Limiting Daily Exposure Time [hours] | Sound Pressure Level [dB(A)] |
| 16 | 70 |
| 8 | 75 |
| 4 | 80 |
| 2 | 85 |
| 1 | 90 |
| 30 minutes | 95 |
| 15 minutes | 100 |
| <8 minutes | 105 |
| <4 minutes | 110 |
| <2 minutes | 115 |
Typical levels experienced in daily life are: Rock band 110 to 120dB(A), Jet fly-by at 300m or car horn at 1m 100 to 110dB(A), operating a petrol grass mower 90 to 100dB(A) or even something as inocuous as operating a food blender or walking down a busy urban street you would be exposed to a sound pressure level of 80 to 90dB(A).
See also: Action Level, dBA, Hearing, Hearing Damage, Sound Pressure Level, Temporary Threshold Shift.
Subjects: Audio Noise & Vibration