iPhone 5's new video interfaceSprint customers looking forward to the iPhone 5’s improved call quality, prepare to be disappointed.

Sprint today has confirmed via Phone Scoop that its network is incompatible with the iPhone 5 version of HD Voice.

“HD Voice” is the buzzword given to wideband audio, a technology that improves audio quality over phones by extending the frequency range of audio signals. Sprint heavily pushed the technology as a part of its launch of the HTC EVO 4GE LTE and is working on rolling out the technology across its network.

AT&T and Verizon have already said their networks are incompatible with the iPhone 5’s HD Voice. In all, only 20 of 240 carriers worldwide will support the feature at launch, which goes to show how ahead of the curve Apple is with the technology. Maybe the iPhone 5 will be the kick in the pants carriers need to really get going.

We’ve reached out to Sprint for more details on the situation and will update this story when the company responds.