Sound - Abatement vs. the Distance from Source

Calculate sound pressure level reduction with distance from a noise source using the spherical and half-spherical distance formulas. The sound pressure decreases with distance, where doubling the distance reduces the sound pressure level by approximately 6 decibels.

Calculator

Inputs

Directivity Coefficient (D)

Density of Air (ρ) (kg/m³)

Speed of Sound (c) (m/s)

Sound Power (N) (W)

Distance from Source (r) (m)

Results

Sound Pressure (p)-- Pa

Sound Pressure Level (Lp)-- dB

Distance (m)	Sound Pressure Level (dB)	Attenuation from 1m (dB)
1	91.00	0.00
2	84.96	6.04
3	80.47	10.53
4	77.96	13.04
5	76.00	15.00
10	71.00	20.00
20	64.96	26.04
50	56.00	35.00
100	50.00	41.00