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"Huh, Wah?" alert: High-Def VoIP

The VoIP Girl kicks off a rapidly morphing discussion about HD VoIP. "HD," as in High-Def.
Written by Russell Shaw, Contributor on

The VoIP Girl kicks off a rapidly morphing discussion about HD VoIP. "HD," as in High-Def."

"Is HD VOIP something that consumers should consider when choosing a VOIP service, or is it more marketing lingo to work through?," she writes. "As I understand it, HD, high definition, or wideband VOIP refers to voice sampling at 16 kHz rather than at the measley 8 kHz supported by the PSTN and just about everyone else. If you capture voice with a wider spectrum of frequencies, the quality is better."

But as Leanne (The VoIP Girl) points out, there's a catch. Sheesh, isn't there always?

"Sounds good to me, but the catch is you have to have HD end to end in a VOIP call. It's no good having 16 kHz at one end and 8 kHz at the other. In fact, 16 kHz downsampled to 8 kHz (which happens if you are calling a landline) may sound worse than 8 kHz from start to finish.So I guess you can make the argument that HD or wideband VOIP is wasted on the masses when most calls travel partially over the PSTN or use VOIP networks using an 8 kHz voice capture process."

My fellow VoIP bloggers are starting to weigh in. Hey, Techmeme's noticed, so it must be news, right? Eh?

Alec writes:

Wideband CODECS have been around for ages, but because most calls terminate on the PSTN where the standard is 64k G.711 encoded at 8 bits, the fact that a PC-based client can generate and receive wideband audio is meaningless.
It could be one of three things, in my opinion:

  1. Better handling of audio on the PC itself.  Both GIPS and Diamondware have convincingly shown that audio quality can be dramatically improved by paying attention to jitter, and other parts of the audio subsystem, not just the CODEC.  This would impact all calls made, not just calls from one Iristel customer to another.
  2. A wideband CODEC.  As noted previously, this only has an impact if both users are on PC’s capable of supporting that wideband CODEC.
  3. Bog standard G.711 throughout their network.  Some operators will use more highly compressed audio on various legs throughout the network, resulting in lower quality.  If Iristel were to do this, it would undoubtebly improve quality, but they wouldn’t be the only ones to try this gambit. 

For a rather less technical but measurably more jaded look we go to John Biggs at CrunchGear..

John thinks all this is, is marketing speak. And after being assaulted by all those mostly groaner Super Bowl commercials,that's the way my Kona Coffee-d brain is tracking this a.m. 


"What the heck? HD VoIP is apparently the latest marketing scheme by Canadian telco Iristel. Apparently it adds CD quality voice calls to standard VoIP which is, to put it lightly, about as useful as… I don’t even know. Sounds essentially like bullxxxx" (wash your mouth, John).

Then John gives us a reality check. 

"Generally, friends, VoIP is fairly low quality simply because it can be. If you want high quality VoIP get a nice headset and download Skype," he advises us to do. "It’s not like your telephone can reproduce the wonderful glottals of Mariah Carey through a tinny speaker and ’50s-era amplifier."

Um, John, "wonderful glottals of Mariah Carey?"  



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