Is it possible to intercept voice data during call?

Question

I plan to develop Android application which will encrypt/decrypt voice data such that parties can communicate using secure channel. So the question is: how to intercept voice/au

Answer 1

if you are able to access low level libraries and used it to encrypt voice to send it directly through the voice channel off course it would not be possible for the called party to receive and decrypt the signal but if you modulate encrypted voice data and transform this voice data into speech like waveform and send through the voice channel of GSM then surely other party will receive and decrypt the voice.