A method of calculation for average noise level in a room considering the relative position of noise source and sound absorbing surface

摘要

If a sound absorbing surface is sited near the noise source in a room, the direct energy from the source ought to incident upon that surface according to its solid angle ratio and the reflective energy incident upon the surrounding room surfaces in those area ratios. Adopting this idea, we have shown a calculating method for the average noise levels in the room, and found the noise reduction can be expected more effectively when the room has small sound absorbing power and the sound absorbing surface has the large absorbing coefficient. Also we have measured the noise levels in the room including the sound absorbing surface near the noise source. Our experimental results almost agree with the culculated results, and we have confirmed the validity of the proposed calculating method.