Forums > MaxMSP

White Noise Detector

September 8, 2009 | 3:28 pm

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


September 8, 2009 | 8:28 pm

noisiness~ ??


September 8, 2009 | 9:00 pm

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

– Pasted Max Patch, click to expand. –

September 8, 2009 | 11:45 pm

???

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.


September 9, 2009 | 10:08 am

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.


September 14, 2009 | 3:55 pm

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


September 26, 2009 | 10:57 am
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


Viewing 7 posts - 1 through 7 (of 7 total)