For a brief moment during yesterday’s keynote, Apple mentioned that along with some new LTE and battery wizardry, they were able to add support for “wideband audio” phone calls. Some tech people are calling it HD Voice, because it’s really just higher quality voicecalls.
The iPhone 5 supports HD Voice, but you’re never going to be able to use it in the U.S. right now, and you probably never will. Why? Well, there are a lot of messy technical details behind it, but here’s the simplest explanation.
As detailed by PCMag, HD Voice uses a different compression method than previous voice calling systems. The new compression methods of HD Voice allow a phone to handle background noise better, and it improves the representation of all voices so they’re not all robotic sounding.
There are three ways to do HD Voice calls right now. You can use a codec called AMR-WB over a 3G GSM network like AT&T and T-Mobile, but they’re so busy rolling out their 4G networks that they won’t support it. The second way is to use the new EVRC-NW codec on an 2G CDMA 1x Advanced network like Sprint’s, but the iPhone 5 doesn’t support that method.
The third way to get HD Voice calls is through VoLTE (voice-over-LTE). Piping voicecalls through VoLTE is the biggest change to voicecalling since the invention of cellphones. It basically pipes all voice calls over the LTE network, and Verizon has demoed it in the past, and plans to roll it out in the future, but the iPhone 5 doesn’t support it.
So with the mixture of the crazy changes currently underway on each carrier, combined with the limited HD Voice support on the iPhone 5, you really shouldn’t get too excited about HD Voice just yet. Yes, someday you will be able to hear all the subtle sighs, whispers, and rantings of your friends in crystal clear quality, like they’re really standing next to you, but until HD Voice gets some more support form Apple and the carriers, it’s still a few years away.