That's because state of the art vocoders (as used in VoIP) are voice synthesisers. The encoding process breaks your voice down into a series of coefficients, w

That's because state of the art vocoders (as used in VoIP) are voice synthesisers. The encoding process breaks your voice down into a series of coefficients, which are sent sent to the decoder (voice synthesiser) at the other end. When you talk to your Mum on any modern phone system, there's an argument that you're actually speaking to a voice synthesiser that sounds like her. Maybe we need to view the thought process as the person rather than the voice?