Gone with the wind, especially the noise!

Gone with the wind, especially the noise!

Noise pollution carried by the wind

Noise is a complex mix of sounds which produces an audible feeling considered as disturbing or dangerous.
A noise is characterized by it frequency (bass or treble), its acoustic intensity (power) and duration. What makes the difference between a noise and a sound is its perception. It varies in the contexts and with individuals.

Sound propagation is considerably affected by the wind speed and direction.

“The wind speed increases with altitude (wind gradient). As a result, sound waves propagating upwind are refracted upwards and those propagating downwind are refracted downwards.
Therefore, we observe that:
– the area favourable for sound propagation is situated down the wind from the sound’s source
– the sound’s .propagation decreases when the listener is situated in the area where the wind blows against the sound’s source direction”

Propagation du son en fonction du vent

extracted from:
Acoustique environnementale
Chapitre 04 :Propagation du bruit dans l’environnement
Ing. M. Van Damme
Download the paper (in French)

How to better understand noise pollution

The CV7-V installations completed by « iac sim engineering » in Dunkirk include wind data to sound level observation. These data are directly available on an Internet web site as live monitoring Internet de DKBell (Please, wait for the download data).
Wind information is displayed beside a graph featuring the sound level, thus informing the user about the direction in which the noise is carried.
noise pollution graph