It will only hit areas in Illinois, Indiana, Minneapolis and Wisconsin and would require an HD Voice-enabled phone
AT&T is finally activating the HD Voice in its network starting from the 23rd of May but this comes with a catch, in fact more than one catches. When we say HD Voice, we mean the VoLTE-based version which clearly means that an LTE network will be required which must not be confused with the standard HD Voice. However, you can still keep using the data while talking. Before you start getting happy about this new announcement, there are a few things which might put you down in the spirits.
The HD Voice is not going to reach all areas; AT&T has only decided to roll out the new HD Voice in selected areas and in order for two people to communicate, they both need to be in those areas where the HD Voice has been activated and this are the parts of Illinois, Indiana, Minneapolis and Wisconsin. Moreover, you also need an HD Voice-enabled phone and so far only the Samsung Galaxy S4 mini qualifies. And surprisingly, not even the bigger Galaxy S4, or the newer Galaxy S5 fall under this category.