Sound
Copyright 2002 David A. Wheeler, Ph.D., PHR, CMT
NoStress@mail.com Last
updated 09/19/05 01:54 PM
File: sound.htm
Decibels = 1/10 Bel
Logarithmic Scale
| 0 dB |
|
Threshold of human hearing |
| 10 db |
10x |
|
| 20 db |
100x |
|
| 30 dB |
1000x |
whisper |
| 60 dB |
1,000,000x |
Office environment |
| 90 dB |
1,000,000,000x |
OSHA limit for 8 hr work day |
| 120 dB |
1,000,000,000,000x |
Instantaneous Hearing Damage
Next to speakers at a rock concert |
| 150 dB |
1,000,000,000,000,000x |
Jet taking off at 100ft |
| 180 dB |
1,000,000,000,000,000,000x |
space shuttle cockpit at launch |
OSHA Limit
90 dB for 8 hrs
95 dB for 4 hrs
100 dB for 2 hrs
105 dB for 1 hr
110 dB for 30 min
115 dB for 15 min
120 dB never
Peak sensitivity
A weighted
Low frequency vs High Frequency
|
