The failure of traditional traffic noise control for quiet areas
Konferensbidrag (offentliggjort, men ej förlagsutgivet), 2004

One can consider the acoustic soundscape as consisting of two parts the direct acoustic soundscape and the diffuse acoustic soundscape. This fact has important consequences when attempting to change the acoustic soundscapes. The traditional approach to control traffic noise by means of noise barriers or change of traffic distribution is only valid for the areas directly exposed from sources (direct acoustic soundscape). These areas will experience a certain decrease of sound pressure levels when applying these noise control measures. However there will be a lower limit for reduction due to the presence of a diffuse acoustic soundscape. To control/modify such a diffuse acoustic soundscape has been shown very difficult by traditional means of noise control. Main characteristic of diffuse acoustic soundscapes is the presence of a multitude of sources, distributed over a wide area contributing evenly to the acoustic soundscape in a certain areas. Screening will only lead to a redistribution of sound, however consequences of such a redistribution will not be recognised in a diffuse sound field. Absorption has been identified as a main parameter to control diffuse acoustic soundscapes. Reducing sound pressure levels in shielded areas such as inner-yards can only be achieved by adding acoustically absorbing areas along the transfer path between source and receiver, but especially inside the inner-yard. Redistribution of traffic flow has been shown to have a tremendous effect on the directly exposed side, but only a small effect in shielded areas.

measurements

balcony

quiet area

calculations

traffic noise

barrier

sound propagation

soundscape

Författare

Wolfgang Kropp

Chalmers, Institutionen för teknisk akustik, Vibroakustik

Jens Forssén

Chalmers, Institutionen för teknisk akustik, Vibroakustik

Mikael Ögren

Chalmers, Institutionen för teknisk akustik, Vibroakustik

Pontus Thorsson

Chalmers, Institutionen för teknisk akustik, Vibroakustik

Proc. Inter-Noise 2004 (and 33rd International Congress and Exposition on Noise Control Engineering), Prag, Czech Republic, August 22-25 (2004).

Ämneskategorier

Strömningsmekanik och akustik