[PD] obscuring voices while maintaining intelligibility

Mathieu Bouchard matju at artengine.ca
Thu Sep 22 01:51:00 CEST 2011

Le 2011-09-21 à 16:44:00, Hans-Christoph Steiner a écrit :

> I'm currently thinking that a ring modulator would work well for this, 
> and it uses minimal CPU.  Can anyone think of a way to reverse the ring 
> modulation?  I attached my quick sketch.

When the frequency and the phase of the [osc~] are known, then you can 
[/~] by the [osc~]. If not, you need to discover the frequency and phase.

If you send a DC as the input, then the output will be the modulator with 
the correct phase and frequency. Then you can [fiddle~] it.

If you can't produce a DC input for some reason, then... if you produce a 
tone as the input, you can divide the output by your tone, and obtain the 

But if there's a delay and/or other filter (such as a speaker-mic pair) in 
the system, then you need to find the phase difference for your tone. That 
is, if the invertor is a separate device that you carry around to invert 
ring modulations, you will need to find the phase difference.

| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC

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