Cross Time Frequency Spectra Applied to Automotive Brake Noise

We apply a local cross-correlation method to the study of correlating brake sounds perceived inside a car to the vibration produced by the brakes at the source. The method allows one to correlate the time-varying spectral properties of two vibration or acoustic sources. The aim is to identify the possible objectionable sounds by determining the time-varying frequencies that the two sounds have in common. The method utilizes cross-timefrequency distributions, and in particular we use the crossspectrogram. Examples are given to show the effectiveness of the method.