Abstract: The human auditory system possesses remarkable abilities to analyze, process and recognize signals. Therefore, it is feasible to build the mathematical model of the human auditory system and apply it to analysis dynamic signal. An auditory model, ZCPA (the output is called auditory spectrum), is introduced to analysis mechanical vibration signal. By analyzing measured signals, the representation effects of the auditory spectrum for stationary signal, non-stationary signal and the signal with sudden changes are tested. Based on the analysis results, some characteristics of auditory spectrum are revealed and their mechanisms are interpreted. The investigation shows that the auditory spectrum can represent general frequency structure of signal using a few data, especially can obviously represent intermediate and high frequency weak signal components and instantaneous sudden changes in signal.