I want to get some sort of garbling effect over voice audio files. sox has many effects available, but I don't know how to get the desired result.
sox man page, listing available effects.
This is an example of the original voices, and this an example of the resulting audio. I would like to get as close as possible to the second example, although a similar distorsion would be acceptable as well if it sounds fine.
If it's not possible with sox, but you know how it might be achieved, please, let me know.
Just for clarification, sox is a command line program for audio manipulation.
Ring modulator distorsion with SOX
Thanks to the answer I've been able to achieve the effect using solely sox. Here's an example.
Create sinus wave (40 seconds long).
sox -n -r 22050 sine-500.wav synth 40.00 sine 500
Multiply it by the input we want to distort (should have the same duration and sample rate).
sox -T voice-input.wav sine-500.wav distorted-voice-output.wav
The sinus wave can still be heard in the back. You can filter it like this. (The sine wave had a frequency of 500 Hz).
sox output.wav output-filtered.wav sinc 750-250