Sound metric design for evaluation of tonal sound in laser printer

Abstract

The operating sounds radiated from laser printers include tonal noise components caused by rotating mechanical parts such as the gears, shaft, motor, and fan. The negative effects of tonal noise components need to be considered in the process of developing sound quality indices for the quantitative evaluation of users’ emotional satisfaction in terms of psycho-acoustics. However, in a previous study, it was confirmed that Aures’ tonality did not have sufficient correlation with the results of a jury evaluation. Sound quality indices based on loudness, articulation index, and fluctuation strength have problems in considering the effect of rotating mechanical parts on the sound quality. In the present study, to solve the tonality evaluation problem, the calculation algorithm based on Aures’ tonality was investigated in detail to find the cause of decreasing correlation. A new tonality evaluation model was proposed by modifying and optimizing the masking effect, loudness ratio, and shape of the weighting curve based on the basic algorithm of Aures’ tonality, and applied to two kinds of operating sound groups in order to verify the usefulness of the proposed model. As a result, it has been confirmed that the proposed tonality evaluation model has sufficient correlation and usefulness for expressing tonality in the operating sounds of laser printers. In the following study, these results will be used to model sound quality indices as the input data by using the classification algorithm.