Free Noise Reduction Calculator
Calculate the combined noise level when multiple sound sources operate simultaneously.
dB
dB
dB
Combined Noise Level
86.8 dB
After Barrier Reduction76.8 dB
Combined Noise Level vs Sound Source 1 Level
Combining Sound Levels
Sound levels in decibels are logarithmic, so they cannot simply be added.
Formula
L_total = 10 log10(10^(L1/10) + 10^(L2/10))
This converts each level to linear power, sums them, and converts back. Two equal sources produce a combined level 3 dB higher than either alone (not double). A noise barrier reduces the combined level by its insertion loss.
Example Calculation
Two machines at 85 dB and 82 dB with a 10 dB barrier.
- 0110^(85/10) = 316,227,766
- 0210^(82/10) = 158,489,319
- 03Sum = 474,717,085
- 04L_total = 10 x log10(474,717,085) = 86.7 dB
- 05After 10 dB barrier: 86.7 - 10 = 76.7 dB
Frequently Asked Questions
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