Hi,
it would help a lot if you could link to a reference (maybe a YT video or something like that).
Without that one has to guess what kind of transmission you have in mind.
If it is a digital (streaming, uncompressed) transmission, you can have all kinds of "mess up" that renders the audio completely useless (byte swapping being one example). You could fake that effect by doing some ring modulation on a rectangle based waveform and mixing that with a (heavily distorted/overdriven) copy of the original sound.
With analog transmissions one way would be to simply mix n static noise that you can record from some AM radio sweep, dampening out your original audio.
With cell phone like transmissions (packeted digital data) you could block out the original signal, adding in some echo with reduced frequency range, maybe introducing some ringmodulated "disturbance" as well.
I hope something in here can get you started!
Marc