HD Voice

The bandwidth of the telephone connection between our homes and the telephone network hasn’t changed in my long lifetime. Although some noise has been eliminated in long distance calls (sometime and if we’re not on a cellphone), voices on the phone still sound like they did sixty-five years ago. We’ve trained ourselves to accept the clipped quality of a telephone voice with its lack of emotional overtones.

You wouldn’t dream of listening to music over the phone. You expect and get much better sound quality from almost any radio and on TV. Movies have Dolby sound. But the telephone is still the telephone.

Guess what? It doesn’t have to be this way. The answer to telephone voice is voice over IP (VoIP) – so long as both parties are NOT on the public switched telephone network.

In the early days of VoIP, we had to save scarce bandwidth and contend with uncertain Internet delivery so we compressed voice even further than the phone network does and made quality even worse. But, today, bandwidth is relatively plentiful and cheap processing power usually lets us overcome any short delivery glitches (technically called jitter). Now high definition voice is not only possible but it’s also being delivered.

My friend Daniel Berninger’s been telling me this for a long time. As CEO of FWD International (in which I’m an investor), he’s insisted that all our new voice applications (like Facebook VoiceMail) be high definition. But, since I have a tin ear and had a cheap set of earphones, I didn’t realize how important high definition voice is.

Yesterday I had a phone call to make to someone in Israel. I tried to place the call on my Vonage phone (cheap rate to Israel). Since Vonage is designed to interface with the traditional phone network and since I was calling an ordinary phone, I would have gotten the usual phone quality if I’d connected. But Vonage said it had no circuits available. I knew the Skype ID of the person I wanted to contact so I put on my brand new headset and called that ID through my computer.

Fortunately the person I was calling is an active Skype user and he was on his computer and saw and answered my Skype call. He apparently had a decent quality headset as well. Skype devotes extra bandwidth – you’re paying for it, not them – to making call quality good when the call is between two Skype users. The quality was not only good – it was superb. Usually when I speak to someone for whom English is not his native language, there is a lot of “what” and “please say that again” and “I didn’t quite understand you” in both directions. None of that. We were on Skype an hour and sound quality made the conversation much better than a phone conversation has ever been.

I used to think the reason I have a hard time understanding people on the phone is because I can’t see their lips and their expressions. Now I realize much of the problem is the terrible audio quality – which we’re so accustomed to – of a traditional phone call.

As more and more of our communication goes over abundant Internet bandwidth and bypasses the telephony last mile and as the handset and headset manufacturers have an incentive to spend a little extra on speakers and microphones to support HD voice, we’re going to start insisting on getting what we’ve been missing. Ironically, voice over IP over a DSL connection over your old copper wires to the phone company (assuming those copper wires support DSL) can be and soon will be better than traditional telephone voice.

Is any more example needed of lack of innovation on the traditional phone network?

BTW, what did I pay for this hour long Skype call to Israel given that I already have a computer and an Internet connection? Nada! Zilch! Skype-to-Skype calls are free anywhere in the world. That’s just money, though; HD voice is priceless.

Comments

[Chris]

HD telephony holds great promise but as someone else said, given the telecoms industry's lamentable record on 'innovation' it's quite likely never to see widepread adoption. BT are promising to be the first in the world to implement a full IP PSTN but they are saying nothing about HD voice.

As part of the preliminaries to the VoIP rollout at a major university, I implemented the G722.2 broadband codec to about 150 users without letting them know beforehand. The feedback was very encouraging, only a few individuals asked to be moved back to G711. Only intra office calls were G722.2, external calls reverted to G711 or occasionally G729. It was very easy to hear the contrast between the two call types but people very quickly adjusted to the differential. Another interesting point was Voicemail. We had previosly implemented visual voicemail, and everyone was retrieving their messages via an apple player in their browser. Listening to a HD vmail message on your PC speakers is quite a different experience to the awful 8k crap that the mobile networks provide.
Having said all that I am still not optimistic about the telecom sector's ability to market innovation. In the early 70s I could have full DDI across the whole of the UK, and an answerphone and the ability to divert calls frm my keypad. Mobility aside, the GSM networks could offer nothing better than that in 1999. Even the innovative SMS feature was a serendipitous, in effect a marketing mistake. Even as far back as the 70's the great hope for both landbased and mobile telphony has been 'Video', remember Cisco's AVVID? It's not happening guys, is it? I dont think the barriers to innovation are technological, they are marketing and probably therefore outside the scope of this forum. How many VoIP PBX phones support HD codecs as standard, only one. Yes, many of the suppliers have the feature as a premium, or more accurately n the premium handset at $200 and upwards. And of course the value of the feature only becomes apparent once the network effect takes place.

[DG Lewis]

Aswath made pretty much all the comments I was going to make (wideband codec is why Skype sounds better, not bandwidth; processing power allows for much more capable codecs than G.711, which is over forty-year-old technology; ISDN had a 7 kHz audio BC but we all know how widespread ISDN adoption for voice was).

He also asks, "I wonder whether we could attach the traditional black phone to an ATA with a wideband codec and still realize the same voice quality?" I think the answer is "no"; the microphones on phones are typically bandlimited at 3.1 kHz in order to comply with FCC Part 68.

[Aswath]

"Skype devotes extra bandwidth – you’re paying for it, not them – to making call quality good when the call is between two Skype users."

Probably they are still using iSAC codec (there have been reports that they have migrated to another wideband codec). If so, the bandwidth that codec consumes is less than G.711 (32 kbps vs 64 kbps, without the overhead). Given the Moore's Law, available processing power is more than sufficient to support these codecs. So it makes sense to use only wideband codecs. Indeed, we should be blackballing any voice application that does not use wideband codec.

Putting on my traditional PSTN apologist's hat, I would like to point out that some 25 years back, ISDN had provisions to support "7 kHz Audio". But alas, ISDN never really caught on.

Apropos Markus's comment I wonder whether we could attach the traditional black pone to an ATA with a wideband codec and still realize the same voice quality?

[Markus Göbel's Tech News Comments]

You can also have such a good sound quality on your normal phone, if it's connected to a top notch VoIP WLAN router like the FRITZ!Box Fon WLAN 7270 from Germany. When both callers use such a device they can talk in MP3 quality, no matter how far away they are.

"FRITZ!Box Fon WLAN 7270 delivers with HD voice (High Definition) a brand-new sound quality for Internet telephony. It supports the Linear PCM 16 and PCMA 16 voice transmission standards with a 16-kHz sampling rate. RFC 3551 defines the application of these standards for Voice over IP (VoIP), enabling top voice quality in phone calls."

Markus Göbel's Tech News Comments:
AVM has started to sell one of the coolest VoIP devices ever
http://www.goebel.net/technews/2007/12/avm-has-started-to-sell-one-of-coolest.html