Noise Pollution Calculator
Calculate combined sound levels from multiple noise sources and estimate safe exposure time based on OSHA standards.
Combined Sound Level
81.2 dB
Combined Sound Level vs Source 1 Level
Formule
## Combining Noise Sources Sound levels in decibels are logarithmic, so you cannot simply add them. Two 80 dB sources produce 83 dB, not 160 dB. ### Formula **Combined dB = 10 x log10(10^(L1/10) + 10^(L2/10))** ### OSHA Exposure Limit **Safe Hours = 8 / 2^((Combined dB - 90) / 5)** OSHA permits 8 hours at 90 dB, with halving for each 5 dB increase.
Exemple Résolu
Two machines produce 80 dB and 75 dB respectively.
- 0110^(80/10) = 100,000,000
- 0210^(75/10) = 31,622,776
- 03Sum = 131,622,776
- 04Combined = 10 x log10(131,622,776) = 81.2 dB
- 05Safe exposure = 8 / 2^((81.2 - 90)/5) = 8 / 2^(-1.76) = 27.1 hours
Questions Fréquentes
Why can't I just add decibels?
Decibels are on a logarithmic scale. Adding two 80 dB sources gives 83 dB, not 160 dB. The logarithmic scale compresses huge pressure ranges into manageable numbers.
What noise levels are harmful?
Prolonged exposure above 85 dB causes hearing damage. Common sources: normal conversation (60 dB), lawn mower (90 dB), rock concert (110 dB), jet engine (140 dB).
What is the OSHA noise standard?
OSHA permits 8 hours of exposure at 90 dB, halving the allowed time for every 5 dB increase. At 95 dB, only 4 hours are permitted; at 100 dB, only 2 hours.