The funny thing about this is that last month was wondering the same thing. T-Mobile mentions it briefly on their website, but their device list isn't up to date. So when I brought both of my lines to T-Mobile and picked up two LG G2, I found out that HD Voice is supported and sounds great. There's a tangible difference in the clarity of the sound while speaking to someone on HD Voice. It only works on T-Mobile's network and only on HSPA (4G) that I've tested. Basically any mid-range and high-end phone from 2013 on T-Mobile will support HD Voice.
You'd think that T-Mobile would promote it a lot more, but alas they do not.
Posted via Android Central App