When noise is detected, be sure your hearing is protected!
How loud is too loud?
Noise is measured using the decibels (dBA) scale. A normal conversation will reach about 60 dBA. Vehicle traffic on a busy street is about 80 – 90 dBA. A jet engine can reach 140 dBA. Noise levels below the mid-80 dBA range are not expected to cause hearing damage. For example, 85 dBA continuously for no more than 8-hours in a shift is considered an acceptable workplace exposure level.
However, as the noise level increases, the amount of time considered acceptable begins to drop. In fact, for every increase of 3 dBA, the amount of time considered acceptable is cut in half.
So while 85 dBA is acceptable for 8 hours without using hearing protection, at just 88 dBA the maximum acceptable time is 4 hours for a work shift. At 91 dBA the acceptable time is 2 hours.
The NIOSH chart shows the relationship between noise level & acceptable exposure time. Exposure to a very high noise level for a short period can be just as hazardous as exposure to a lower level for a much longer period of time. So always play it safe.