HTC has been making headlines all week with the release of their very impressive new line of phones. The HTC One X and One S were met with rave reviews by tech sites all across the web, and last night Sprint and HTC announced the HTC EVO 4G LTE, which takes more than a few design cues from the One line and mixes them with some EVO flavoring. The unveil last night included some really great technology crammed into a very thin and solid design, and EVO users get their kickstand back! The phone also comes with some interesting new voice technology, being branded as HD Voice.HD Voice, previously called Wideband Audio, promises to deliver a higher quality audio experience by replacing the narrowband audio limitations found in traditional phone calls. There’s a small hitch in this plan though — Sprint’s network isn’t going to see Wideband Audio for quite a while.Preparing Sprint’s network for an infusion of Wideband Audio is something that has to be rolled out market by market. It’s not as simple as throwing a switch, in fact the networks have to be capable of transmitting the extended frequency range, and making sure there is appropriate bandwidth for the higher quality codecs. The reality is that each phone call uses significantly more bandwidth using this technology, in order to deliver that higher quality experience. Now, in the age of mobile data traveling faster than the average consumer’s home internet connection, Wideband Audio is a possibility.Wideband Audio isn’t exactly new. The ITU standardized the concept back in 1987, but just last month the FCC proposed the ruling to allow for existing networks to be modified to support this technology. From this point, Sprint can start upgrading their towers to support Wideband Audio. Unfortunately, that’s going to take some time.According to Sprint, their upgrade plan for Wideband Audio is supposed to begin in “late 2012” and continue into 2013. Sprint has not yet released any information regarding which areas will receive the upgrade first, but according to their roll out plan 14 markets will receive the update in 2012. By the end of this year, Sprint plans to have multiple devices on their network that can support Wideband Audio calling. It is a reasonable assumption that at least most of these devices will also be a part of Sprint’s budding 4G LTE network deployment, set to begin rolling out this summer. By the time Wideband Audio is on Sprint, the carrier will undoubtedly tout the technology as a great addition to their network. Unfortunately, it’s really not the selling point it appears to be, even after it has been rolled out.Wideband Audio calls only happen if both sides of the call are using the technology. The person answering the call has to answer with the same codec, or the phone will be forced to drop down to a narrowband codec for the call. So, by the end of this year, as long as Sprint rolls out multiple devices like they plan to, you’ll only be able to enjoy that higher bitrate phone call with other people on Sprint, with a Wideband phone, in a Wideband Market. The list of people in your contacts list that this new feature applies to gets smaller and smaller the more you think about it. The other carriers aren’t looking at Wideband Audio right now. Verizon Wireless was considering it for a time, but has since moved on to Voice over LTE, and neither T-Mobile or AT&T have announced any official plans for the future of their voice calls.Will Wideband Audio turn out to be another wasted effort on behalf of Sprint? Will it carry on for a time like WiMAX and then be replaced by something like VoLTE in order to support more users? There’s a lot of unanswered questions for this technology that lead me to have significantly less faith in how amazing it will be. Dan Hesse took to the stage last night and proudly announced HD Voice as the future of mobile calling. While I remain unconvinced that it will be that exactly, it is a very good sign that at least some of the carriers are starting to re-evaluate the state of the mobile phone call, and taking steps to improve things. Who knows, maybe this time next year that guy standing next to you at a concert with his phone in the air will actually be delivering a quality audio experience to the person on the other end of the call.