> My phone is an IP phone. It doesn't do SMS. Did you mean "mobile phone"?

UK landlines are transitioning to VoIP. SMS messages sent to UK landlines are read out by a text-to-speech system (well, my parents' does).

Yes; mine does that too. Have you ever tried to use one of those TTS systems? They can just about read standard international English; anything more interesting, like someone's name, and they fall back to spelling-out the letters.