Sprint makes a bold claim it is the first U.S. carrier to announce plans for a nationwide HD voice network beginning in late 2012. Strictly speaking, that’s true. However, Verizon Wireless (News - Alert) is planning to deliver voice over LTE (VoLTE) starting sometime in 2012, with a nationwide rollout in 2013. In addition, MetroPCS has its hat in the VoLTE ring while AT&T (News - Alert) and T-Mobile USA could conceivably roll out HD voice in short order via software and firmware upgrades. The truth, I suppose, depends on your point of view.

Clearly, Sprint has made the loudest official claim to HD voice in the U.S. with its April 4 announcement introducing the (deep breath here) HTC EVO 4G LTE (News - Alert) phone. The company chose HD voice as the first feature to highlight in the press release, along with network support for HD voice. Further, Sprint is the first CDMA carrier to announce HD voice using Qualcomm’s (News - Alert) 1X Advanced and EVRC-NW technologies.

However, Verizon Wireless threw its ring into the mobile HD voice sweepstakes last year by demonstrating VoLTE at Mobile World Congress using Android (News - Alert) smart phones. Verizon said it would roll out VoLTE “sometime” in 2012, but never put a date certain on the calendar. VoLTE’s default codec is AMR-WB – the same HD voice technology being deployed on HSPA networks around the globe from Armenia to Uganda, so a VoLTE call is by definition an HD voice call.

No doubt there will soon be dueling press releases, executive statements, and a lot of discussion over who has the better/best HD voice quality and widest coverage. Sprint may have an interesting upper hand by starting with HD voice on its 3G CDMA network and then rolling out VoLTE onto its LTE network in 2013. Verizon Wireless hasn’t said anything about introducing 3G HD voice, preferring to emphasize its LTE network.

Both firms may be beaten to the punch by MetroPCS, which said it will roll out VoLTE in the second half of this year. MetroPCS is under the gun to shift from CDMA to LTE operation as soon as possible since it has a relatively limited amount of spectrum to work with and doesn’t have the luxury of operating two networks in parallel over the long term. The sooner it moves its customers over to LTE, the sooner it can “refarm” its CDMA spectrum into LTE use.

Dark horses in the U.S. mobile HD voice race are AT&T and T-Mobile USA. Both companies have clear cut LTE deployment plans, but both also have HD voice-capable HSPA networks. Vendors such as Ericsson have noted both companies already have the network hardware and phones to run HD voice; it’s simply a matter of flipping the appropriate software switch to deploy AMR-WB on the network.

If anyone has an incentive to turn on HD voice on short order, it’s T-Mobile USA. The move would show it is continuing to lead and compete in the U.S. while it deploys its LTE network.