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

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Formula

## 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.

Esempio Risolto

Two machines at 85 dB and 82 dB with a 10 dB barrier.

  1. 0110^(85/10) = 316,227,766
  2. 0210^(82/10) = 158,489,319
  3. 03Sum = 474,717,085
  4. 04L_total = 10 x log10(474,717,085) = 86.7 dB
  5. 05After 10 dB barrier: 86.7 - 10 = 76.7 dB