The optimum level of music listened to in the presence of noise

Abstract

The optimum level of music listened to in the presence of noise is studied and discussed from the point of masked loudness. By carrying out an experiment with five pieces of music, it is revealed that the increase in the optimum level of music is about 3dB against 10dBA noise level increment if the noise level lies between 55dBA and 75dBA. The increment of the optimum music level is less as compared with the above value for a lower noise level than 55dBA, and greater for a higher noise level than 75dBA. Even if the signal is radio news instead of music, this rate of increase seems to be unchanged. This tendency of the consistency of the optimum level may be attributable to the subjects' judgement that they intend to keep the masked loudness of music constant against the change of noise level. Selecting a standard signal, we carried out a simulation test to derive the standard equal loudness contour for the signal against various noise levels. Since these contours well simulate the experimental curves, they can be used as the standard for designing an automatic level controller such as that assembled in the playback system used in the presence of noise.