Gone with the wind, especially the noise !

08 Jun 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.
Noise can be characterized by its frequency (low or high), its acoustic level (also called intensity), and its duration (short or long). What differentiates noise from sound is the perception we have of it. The perception of noise varies according to the context and the individual.

Wind direction and speed are important factors affecting the propagation of sound

“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”

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

The CV7 installations completed by « iac sim engineering » in Dunkerque include wind data to sound level observation. These data are directly available on a website 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.