A psychoacoustic approach for sound quality assessment of automotive power windows

Psychoacoustic methodologies were investigated and applied to a case study within a cooperation project of the University of Pisa and Magna Closures S.p.A. mainly focused on the acoustics of power windows. The project included tests on closing-opening event sequences of the power window rail, to evaluate the component noise. Different trials were performed varying the test conditions. Time-frequency analyses, psychoacoustic metrics and models were applied to the Sound Pressure Level (SPL) time functions of the raw microphone signals and compared with threshold values from the literature. Scalar parameters quantifying the electric motor steadiness were also computed to characterize the noise excitation source while accelerometer signals were analysed in the frequency domain to extract modal parameters. The SPL time function appeared highly related to supply voltage, motor type and silent block insertion whereas psychoacoustic parameters were able to highlight further peculiarities of sound timbre.