Psychoacoustic Model for Perceived Fluctuation of Vehicle Interior Wind Noise

Abstract

Vehicle interior wind noise (VIWN) generated by aerodynamic flow is one of the major factors affecting the pleasantness in a vehicle passenger compartment, especially in the high-speed condition. In particular, fluctuating wind noise can be perceived as more annoying at a high speed. Therefore, the present study aimed to investigate the characteristics of the fluctuation of VIWN and to develop its psychoacoustic model. In the first experiment, VIWN was considered to consist of a carrier noise (partially weighted pink noise) and various amplitude-modulation components. Subjective evaluation for 25 stimuli was performed by a total of 12 participants

thereafter, modulation strength (MS) was proposed to fully explain the subjectively perceived fluctuation of the VIWN. The results of correlation analysis showed that the MS of octave-band scale were more strongly related to the subjective evaluation of the VIWN fluctuation than loudness or fluctuation strength. In the second experiment, to verify the effectiveness of the MS, 19 stimuli recorded in a wind tunnel were used. The results showed that three parameters (loudness and the MS of 7th and 8th octave bands) were highly correlated with the subjectively perceived fluctuation of VIWN. Based on the results of hierarchical linear regression analysis, it was concluded that the MS of 7th octave (fc =4000Hz) can fully explain the subjectively perceived fluctuation of VIWN. Therefore, in the present study, the MS of the 7th octave band was determined as the psychoacoustic model for the VIWN fluctuation.