Distance Attenuation Explanation

Distance Attenuation Explanation

● The reduction in sound pressure level as the distance from the sound source increases.

Point source SPL₁- SPL₂= 20log(r₂/r₁)

Line source SPL₁- SPL₂= 10log(r₂/r₁)

SPL: Sound Pressure Level (dB), r: Distance

Example

When the distance between a point source and a free sound source is 5m, and the sound pressure level is 88dB, what will be the sound pressure level when the distance changes to 16m?

To calculate the sound pressure between the point source and the free sound source:

SPL₁- SPL₂= 20log(r₂/r₁)

By substituting SPL₁= 88, r₂=16, r₁=5 into the formula:

88 - SPL₂= 20log(16/5)

Therefore, SPL₂= 77.9dB

Conclusion

Distance attenuation of sound demonstrates that the sound pressure level changes as the distance between the sound source and the listener increases. Understanding this plays a crucial role in acoustical engineering and environmental noise control. Keywords: Distance Attenuation Sound Pressure Level Point Source Line Source Acoustical Engineering Environmental Noise Control Sound Source Distance dB Sound Level Change