White Noise Detector

Sep 8, 2009 at 3:28pm

White Noise Detector

Hi,
I’m using this object fiddle~ trying to catch the white noise. I need some help with this method, because I don’t have a clear analysis of the noise, I need to have a trigger only when the white noise is real, not when someone is just talking. Somebody could help me with this?
Thanks
David

#45386
Sep 8, 2009 at 8:28pm

noisiness~ ??

#163582
Sep 8, 2009 at 9:00pm

If what you’re looking for is *really* white noise,
you could always try something simple like

– Pasted Max Patch, click to expand. –
#163583
Sep 8, 2009 at 11:45pm

???

Gregory? Just curious… wouldn’t you want to measure phase coherence ? A sine sweep up the spectrum takes that meter from empty to full, none of that’s noise. Is this more of a pragmatic approach? I’ve never seen it before.

#163584
Sep 9, 2009 at 10:08am

any fft-based analyzer with something like 4-5 frequency sections,
no matter at which exact positions, should work fine for finding
“white noise”, even fffb~ maybe.
with tristan´s it is easier of course.

#163585
Sep 14, 2009 at 3:55pm

You might want to give a try to zsa.descriptors. zsa.spread~ or zsa.slope~ might do the trick.

#163586
Sep 26, 2009 at 10:57am
Matthew Aidekman wrote on Wed, 09 September 2009 01:45
A sine sweep up the spectrum takes that meter from empty to full, none of that’s noise. Is this more of a pragmatic approach?

I bet it is. any fixed high frequency will produce enough zero crossings to count. In the scenario David describes it seems perfect, as you usually won’t have just high frequencies on a sustained sound. The normal frequency distribution is characterized by a majority of relatively lower frequencies, and with speech, a lot of pauses…

Stefan

#163587

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