How do i find the ZCR of a speech signal?

For an assignment we need to develop a suite for a speech signal, plotting time domains like RMS, Peaks and ZCR. Id just like to know how id go about obtaining the ZCR and how exactly id plot it, what can i expect? Im very new to the MATLAB software.

Answer 1

[Star Strider]

The easiest way is to use the zerocrossrate function in the Signal Processing Toolbox (however that likely amounts to cheating).

The other option is actually obvious, however writing it out would give it away, so I’ll just hint at it.

The zero-crossing points for a signal are defined as the signal changing signs (positive to negative, or negative to positive). Figure out a way to detect those indices, then use the interp1 function (if necessary) to estimate the most precise zero-crossing points (it will be necessary to do this segmentally in a loop with each zero-crossing for reasons that will quickly become apparent), then do whatever statistics are necessary on the results.

That should be enough of a hint. Have fun with this!

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