Whence HD Voice?

Most of the world's voice traffic is built around capturing a range of sound from 300Hz to 3,500Hz, a range pretty much set back in the days of analog and copper wiring. How come we haven't leaped beyond it?

In the radio world, ISDN digital voice service remains popular for its ability to deliver 15kHz to 20kHz of sound before broadcast, making for a richer and clearer experience and providing an "in studio" experience as opposed to guest callers delivered either via wireline, or worse yet, cellular.

Within the VoIP community, it's been about two years since the open source community first started plugging away at moving voice quality uphill to 16kHz or 32kHz. WYDE Voice has generated a lot of excitement around its VM1000/VM300 series of conference bridges, and for good reason. The appliances are built with Asterisk (Hi Mark Spencer!) and Aculab's Prosody X media processing technology and are in use at Freeconferencecall.com and some other places.  Skype has also been supporting 16kHz rates in their world.

On the commercial side, Polycom has championed HD voice for audio conferencing, expanding the range of capture between 100Hz to 7000Hz. The company cites studies showing people pay more attention during an HD voice-delivered conference call, with the additional information being able to provide better nuances of emotion and tone. Makes sense; don't you prefer to listen to FM or CDs over AM radio?

Widespread proliferation of HD voice may be stuck in a legacy rut--all those legacy desktop and mobile handsets geared to vanilla 8kHz sound. HD voice communication may be forced through the PC because of its ability to easily download and upgrade codecs--another nail in the coffin for desktop handsets. Unless someone pairs HD voice with a Casabi-enabled handset as the "killer app" to displace vanilla voice services of all types.

Still, when Nick Jensen was on his soap box last week at the Dialogic analyst briefing, I didn't hear him bang the table about HD voice. The ability to transcode between HD video and other formats, yes. High(er) quality voice, no. Video may be the driver and brings HD voice along for the ride.

- Doug