Sound quality evaluation of transient sounds in precision information equipments

Abstract

These days, sound quality in mechanical products has become a very important factor in addition to reduction of the sound pressure level. A new method is proposed for sound quality evaluation including the transient sound in precision information equipment taking MFP (multifunction peripheral), for example. The MFP has many functional parts and a lot of operational modes, so single copy mode and ten times continuous copies mode in monochrome are taken into account. Since the operational sound including the transient sound is changed with time in one cycle, it is necessary to identify high contribution sound section to decide the sound quality by pair comparison method and SD method with original, filtered, and edited sounds. As a result, sound quality of the transient sound is influenced by the cycle time, the rhythm, the sound pressure, and the frequency characteristics. As the single copy mode, main uncomfortable sound can be estimated at the steady-state sound section caused by a rotational component. On the other hand, for the ten times continuous copies mode, it can be estimated at the particular transient sound section in one cycle caused by collision with mechanical parts, which is different from the single copy mode.