I never knew I had HD Voice till yesterday when I could not make ANY calls to anyone because I kept getting a message instead of a connection. The message was "HD Voice not available". So this HD Voice thing was completely killing my phone. I could not find any settings to turn it off so I could make a call.
This made me start thinking -- what if it was an emergency? What if someone in my family had been injured (or died) and people were trying to get in touch with me? What if I was on a field trip and one of my students took ill or had gotten hurt and I could not call their parents or the school or even an ambulance? What if I was at the store and forgot what my wife sent me for? And suddenly I can't call any one because for some reason HD Voice is not available.
This is very scary. There really should be some way to turn this off. Really, T-Mobile's system should not stop a call just because some service that you really don't need isn't working. The system should automatically change over to non-HD and connect the call. I think this is one of those "benefits" that's going to get T-Mobile into some serious law suits and maybe get some of their customers killed because they cannot get help.