I don't think that's realistic. If you're looking at the acceleration sound waves cause against a phone's accelerometer, that's likely far below the sensitivity of the sensor- phones are too massive relative to the force of sound waves from speaking. F=ma, so the acceleration you're looking at is the force of the soundwave (tiny) divided by the phone's mass (relatively large). The only reason this kind of works is because you're putting the phone on an object that's mechanically vibrating. I suppose it would work in certain situations like putting the phone on top of a large speaker, but you'd never get the resolution to decipher audio from sound waves alone for a phone sitting on a desk or in a pocket