There has been a fair amount of hype recently surrounding HD Voice. I have been driving Dialogic's strategy for this technology, conducting experiments and talking with industry experts on the subject and there is no question that HD voice will greatly improve voice communications in the near future.
However, there are limitations to HD voice that people need to be aware of. The primary limitation is that if both ends of the conversation and the entire pipe in between are not HD voice capable, then an HD voice conversation cannot be established.
Furthermore, if you do not have an HD capable microphone or speakers, you will not experience any of the benefits of HD voice. The reason for this is quite simple; HD voice has a wider power spectral density than normal telephony audio. This means that in order to reproduce this spectrum, you first need a microphone that is capable of generating it with reasonable quality.
In the pictures shown below, we capture the power spectral density of a recording using the same speaker and the same phrase, only using two different microphones. The first is the integrated PC microphone from a laptop and the second is a microphone designed for wideband audio. The differences are striking
So before you make the investment into HD voice, make sure the benefits can be realized.