I suppose simply using magic to make sounds would be a fairly trivial Imaginem spell.
Voice of the Mute Magus
CrIm3 (Base 1 +1 intelligible speech, +0 Pers, +0 Ind, +1 conc)
Cause an intelligible human voice to emit from a hand which you are using to mimic mouth movements. Creating words at your direction.
It seems like you wouldn't be called down for using telepathy as a mute any more than a blind magus gets called down for scrying when using magic to repair his eyes or see through his familiar. Which is to say you could be called to account but the charge would get voted down in Tribunal for being a waste of everyone's time (unless you pissed a lot of people off).