New tonality design for non-stationary signal and its application to sound quality for gear whine sound

The sound quality for the axle-gear whine sound in a sports utility vehicle was investigated in terms of psychoacoustics. Aure's tonality was considered as the sound metric for the expression of the tonality of gear whine sound in a previous research. However, it did not prove possible to use Aure's tonality successfully as a sound metric for the tonal impression. Aure's tonality did not express well the tonal impression of the gear whine sound as the whine sound is a non-stationary signal with both frequency and amplitude modulation. In this study, the new method for the tonality evaluation for a non-stationary signal is presented. It is developed based on the prominence ratio, tonality impression function and lower threshold level. It improves the accuracy and reliability of the sound quality index being used for the sound quality evaluation of the axle-gear whine sound.