Abstract: A method of distinguishing a first physical phenomenon captured in a sensory measurement time waveform from a second physical phenomenon captured in the waveform includes: receiving the waveform on a processor from a sensor in sensory contact with an object undergoing first and second physical phenomena, wherein the first phenomenon is a comparatively fast event; deriving a first rate of change data stream from the time waveform with a processor operable on a processor, wherein each value of the first rate of change data stream is based on a difference in extreme amplitudes of the waveform during a first interval of waveform samples; and analyzing with the processor the derived first rate of change data stream to distinguish the comparatively fast first physical phenomena from the second physical phenomenon captured in the waveform.