The Zero Crossing Rate (often used in its shortened form ZCR) is the rate of change of sign of a signal. The ZCR was used much in voice recognition and Recherche of musical information. It is defined by:

$zcr\; =\; \backslash \; frac\; \{1\}\; \{T\}\; \backslash \; sum\_\; \{t=0\}\; ^\; \{T-1\}$

where $s$ is a signal length $T$ and $$ is a indicating function which is worth 1 if its argument $A$ is true and is worth 0 if not.

References

• Fabien Gouyon, François Pachet, Olivier Delerue (2000), One the Uses off Zero-Crossing Rate for year Application off Classification off Percussive Sounds , in Proceedings off the COST G-6 Conference one DIGITAL Audio Effects (DAFX-00), Verona, Italy, December 7-9, 2000. Accessed 7th Oct. 2006.