Outdoor Sound Propagation Calculator (ISO 9613-2)
Determine receptor sound pressure level ($L_p$, dBA) from point source sound power ($L_w$) accounting for distance divergence, air absorption, and ground effects.
Source & Propagation Environment
Predicted Receiver Noise Level
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ISO 9613-2 Environmental Noise Standards
ISO 9613-2 specifies engineering methods for calculating the attenuation of outdoor sound during propagation under meteorological conditions favorable to propagation (moderate downwind or moderate ground-based temperature inversions).
Components of Attenuation
Total acoustic attenuation ($A_{tot}$) sums four distinct phenomena: $$A_{tot} = A_{div} + A_{atm} + A_{gr} + A_{bar} + A_{misc}$$ Geometric divergence ($A_{div}$) follows the inverse-square law, delivering a $6\text{ dB}$ reduction for every doubling of distance in free space. Soft ground cover ($G = 1.0$) introduces destructive acoustic interference between direct and ground-reflected waves.