The present invention relates to a vibration signal processing method and system that can be used to account for situations where impact or impulse events are hidden in a normal vibration reading by low frequency vibrations and high frequency noise. In one preferred form, the method of the present invention comprises the steps of obtaining electrical vibration signals that represent mechanical vibrations of a machine (102-106), converting the electrical vibration signals into digital vibration samples (108), dividing the digital vibration samples into equal time intervals and determining the average absolute amplitude of the digital vibration samples for each time interval (110), generating a time waveform comprising the determined average amplitudes (112, 114), and processing the time waveform as if it were an independently-detected signal (116-120).