A signal amplitude saltation often implies fault information of an equipment. In order to recognize the time-frequency domain where a signal amplitude saltation appears, a calculation method of signal saliency map based on the information processing mechanism of an auditory system was proposed. Firstly, auditory peripheral processings, such as, band-pass filtering, phase adjustment and half wave rectification were performed for a signal. Secondly, extracting the envelope information from the results of processings one time or multiple times, they were then processed with the multi-scaled two dimensional filtering. Nextly, the local saliency of the signal under different scales was obtained using the centre-rim difference operator. Finally, the global saliency map and time-frequency saliency map of the signal were gained by means of the multi-scaled integration and the linear combination of local saliencies. The results of tests and simulations showed that the proposed method is applicable to both vibration signals and voice signals, it is effective and practical, it can clearly represent amplitude saltation time-frequency domain of a signal and resist a certain noise interference.