'Hues' sound level meter based on noise-rating scale composed of five-hue scale and equivalent continuous a-weighted sound pressure level and its usefulness

The noise level and the effective noise level used for noise evaluation are physical indices and generally are not understood. It is believed that the understanding of such physical indices can be enhanced if one can realize a sound level meter which can display directly the relationship of the psychological effect by the noise with the measured decibel scale. From this point of view, this paper first evaluates in a laboratory experiment the relationship between the hue level expressing the psychological effect and the effective sound level. According to the obtained noiserating scale, the five-hue scale, “red, purple, yellow, green, blue” and the effective noise level correlate well. Next, a new sound level meter including the obtained noise-rating scale (to be called the hue sound level meter) and the existing sound level meter displaying only the measured value were compared at the actual measurement site. From the comparison, it was found that the hue sound level meter has better visual display and the display represents the auditory sense. From the foregoing results, it is possible to promote general understanding of the physical index.