If people are exposed to very noisy environments, 81 dB or more, ear protection are necessary to prevent ear damage.

If the level of noise is 70 to 83 dB (such as in traffic areas) the maximum daily exposure time would be 8 hours without getting problems. But, if the noise level is 90-100 dB (for example when using power tools) the maximum exposure would be only 30 minutes. When the sound level is 101-120 dB (during concerts), the ears will suffer in only 7 minutes.