http://www.gcaudio.com/resources/howtos/loudness.html
Decibel (Loudness) Comparison Chart
Here are some interesting numbers, collected from a variety of sources, that help one to understand the volume levels of various sources and how they can affect our hearing.
Environmental Noise
Weakest sound heard 0dB
Whisper Quiet Library at 6' 30dB
Normal conversation at 3' 60-65dB
Telephone dial tone 80dB
City Traffic (inside car) 85dB
Train whistle at 500', Truck Traffic 90dB
Jackhammer at 50' 95dB
Subway train at 200' 95dB
Level at which sustained exposure may result in hearing loss 90 - 95dB
Hand Drill 98dB
Power mower at 3' 107dB
Snowmobile, Motorcycle 100dB
Power saw at 3' 110dB
Sandblasting, Loud Rock Concert 115dB
Pain begins 125dB
Pneumatic riveter at 4' 125dB
Even short term exposure can cause permanent damage - Loudest recommended exposure WITH hearing protection 140dB
Jet engine at 100' 140dB
12 Gauge Shotgun Blast 165dB
Death of hearing tissue 180dB
Loudest sound possible 194dB
OSHA Daily Permissible Noise Level Exposure
Hours per day Sound level
8 90dB
6 92dB
4 95dB
3 97dB
2 100dB
1.5 102dB
1 105dB
.5 110dB
.25 or less 115dB
NIOSH Daily Permissible Noise Level Exposure
Hours per day Sound level
8 85dBA
6 86dBA
4 88dBA
3 89dBA
2 90dBA
1.5 92dBA
1 94dBA
.5 97dBA
.25 or less 100dBA
0 112dBA
Perceptions of Increases in Decibel Level
Imperceptible Change 1dB