Digital signal tonality detection - using binary signal conversion controlled by sampling

摘要

The process is for detecting tonality in a digital signal so that the signal is transformed into a binary signal SB such that SB equals + 1 each time the amplitude of a sample of the digital signal is greater than a threshold S+. The binary signal presents a structure of alternating positive and negative parts each valid part being formed from a number n of characteristic samples of the frequency of the signal. A tonality is detected when one finds a number m of valid parts, each formed from a number n of samples, the number m being representative of a complete tonality and being followed by a nonvalid part formed from a number p of samples representative of an absence of tonality.