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HD-Telephony: Hip or Hype?

blogs.zdnet.com — The term “High Definition” is traditionally applied to a technology when a new innovation allows a noticeable improvement in quality or detail from an existing version. The superior picture quality of an HD TV for example. The improvement in telephone audio quality that HD-Telephony offers is far less profound than that of HD-TV or HD-Radio but it’

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briankwest 32 days ago, made popular 31 days ago

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goestelecom, on 04/15/2008, -15/+6What's higher quality than digital ?
- briankwest, on 04/15/2008, -0/+12Higher quality than 8kHz that normal phones run at. 16kHz does sound much better!
  - scubajim, on 04/15/2008, -0/+6Actually the band with is 3kHz from 300 hz to 3300 Hz which is why s's and F's are difficult to distinguish.
    - bryxal, on 04/15/2008, -5/+2your right the difference between 3300Hz and 3kHz is HUGE......
      
      /S
    - scubajim, on 04/15/2008, -1/+3I guess you weren't that good at math 3K= 3300 - 300 The standard for phone lines is to support 300 Hz to 3,300 Hz which is a bandwidth of 3K.(not 8K, phones don't have 8K of bandwidth)
    - veloscaper, on 04/15/2008, -0/+5frequency range and sample rates are not the same thing.
    - Leomarth, on 04/15/2008, -0/+2@veloscaper
      
      Right. Nyquist's law says your sampling rate should be at least 2x your maximum frequency.
- zoid, on 04/15/2008, -2/+21Many audiophiles will argue that analog is higher quality.
  - derek4iax2, on 04/15/2008, -0/+8Yep. Some of them will argue that valve amplifiers give even better quality.
    
    However, 16khz does sound much better than 8khz.
    - briankwest, on 04/15/2008, -0/+4What is nice is G.722 is free and uses the exact same bandwidth G.711 does. So 16kHz at 8kHz prices in terms of bandwidth.
      
      Oh and FreeSWITCH comes with G.722!
      
      /b
  - RustyJ, on 04/15/2008, -2/+5that's because there's zero latency. It is superior. However, it's also impossibly expensive to utilize and maintain.
    - briankwest, on 04/15/2008, -1/+4G.722 isn't to be confused with G.722.1 or anything else with a dot in it. G722 is light on CPU and isn't expensive to utilize or maintain.
      
      /b
  - RealmDown, on 04/15/2008, -0/+15Most audiophiles just like to argue.
- Spuy767, on 04/15/2008, -2/+11I think that HD is the new buzz word for the entire word, I swear to go I've seen every thing termed HD. I know I've seen HD sunglasses at the store, and I've probably seen HD microwaveable pizza. I've seriously had enough of that term.
  - TRScheel, on 04/15/2008, -1/+10High Definition pizza... now that I gotta see
    - nekochan, on 04/15/2008, -1/+6just buy pizza from a local business instead of pizza hut. the colors and flavors will pop.
  - marksism, on 04/15/2008, -3/+14My dictionary is high in definitions
  - loneBoat, on 04/15/2008, -1/+5This is a High-Definition comment. See how clear it is?
    
    Now compare it to a Standard Definition comment:
    Ron Paul FTW! You, sir, win at Internet tubes. I like XKCD! OMG, neocons R crazy!
    
    See how unclear it is? Digg needs to implement HD comments.
    - raynevandunem, on 04/15/2008, -0/+3Wouldn't HD comments have larger (I mean, gratuitously large) text sizes and fonts, as I've seen on some web designers' blogs?
      
      Oh....that's probably Web 2.0 comments. My bad.
- madeingermany, on 04/15/2008, -1/+6Listen to any (properly recorded) podcast that has somebody dialing in and you will know the difference there.
  
  Our company went to IP phones - still the sound quality is not nearly what it could be and don't get me started on those miserable cell phone calls...
- ken0624700, on 04/15/2008, -2/+7actually analog is always higher quality than digital - once you start digitizing an analog signal by sampling it, you lose quality.
  - HonoredMule, on 04/15/2008, -1/+3But not only does a digital signal itself not degrade in quality, digital equipment is free from the decay that drastically shortens analog equipment's lifespan, and increasingly degrades the quality of any signal it handles over time.
    
    Also, the only "perfect" signal would be one that was fabricated by digital process from the beginning. An electric keyboard, for example, loses quality by translating to analog instead of the other way around, whereas a digital signal would precisely represent the original content despite traversal of time and space. As more and more audio is produced or engineered programmatically, analog will lose all advantage.
    
    Then audiophiles will complain about the LACK of impurities...kind of like they do with the familiarity of record scratching.
- anthm, on 04/15/2008, -0/+3Yes, that's what the article is all about. Hence the title =D
geoffhill, on 04/15/2008, -0/+23Now I can argue with my cable company with higher sound quality. Hurray.
- briankwest, on 04/15/2008, -1/+5Not only that but they can tell the F from the S really clearly. So your curse words will make it thru in stunning quality.
  
  /b
  - tuxidomasx, on 04/15/2008, -0/+6Customer Service: Every item on your bill iff sinal and cannot be taken off.
    Me:What? What the SUCK is this FHIT on my bill?!? I didn't order thif!
    
    yup. HD might be worth it.
- sharigan, on 04/15/2008, -0/+1ironically... the argument is about the poor audio quality your currently receiving.
P522, on 04/15/2008, -1/+33The HD in HD Radio stands for Hybrid Digital, not High Definition. There's nothing High Definition or enhanced quality coming out of a cheap HD radio.
- tarmithius, on 04/15/2008, -1/+9So true, I cringe every time someone asks me if it means High Def.
  - Murfshay22, on 04/15/2008, -2/+3Yeah, there's an ad where I live for HD Radio and every time they play it, it cuts back to the station's spokesman saying, listen to us now in High Def!
    It's annoying.
    
    Remember a few years ago, there was some commercial for HD sunglasses?
    - slimjim5811, on 04/15/2008, -1/+2You mean BluBlockers?
- briankwest, on 04/15/2008, -0/+9Same here. Anthony did know that it means Hybrid Digital... But everyone thinks it means High Def.
- logandurand, on 04/15/2008, -2/+4They use "HD" in the name intentionally, knowing people will associate it with high-definition.
  - lengau, on 04/15/2008, -0/+1I thought it as as opposed to AD (all-digital)?
RustyJ, on 04/15/2008, -3/+9There is no such thing as high definition audio, just audio without interference/immaculate mixing. By that logic, XM and Sirius are both "HD radio" as they do not have any FM static. Don't let the salesman suck you into the High-Def Hype
- mjerris, on 04/15/2008, -0/+14Typical phone circuits only pass audio in the 300 to 3400 Hz range, wideband digital audio covers 50 to 7000 Hz. This is a significant difference for example in telling the difference between an "S" and a "F" when spelling something on the phone. You can also increase clarity via higher sample rates. This is not just a matter of interference, this is how much of the audio data you are reproducing vs. what the human ear can detect.
  - elscorcho717, on 04/15/2008, -0/+2While I agree that certain consonant sounds approach and perhaps at times surpass 3400Hz, I think that increasing the sample rate would have a much more noticeable effect on the audio quality coming out of your phone, especially since the one that is used now is ridiculously low.
- Timmmm, on 04/15/2008, -1/+4Yeah that's *****. Phones are narrow-band. Think about it! If you connected a CD played through a phone (directly - not via a microphone) and then into a nice hi-fi on the other end it would still sound *****.
  - briankwest, on 04/15/2008, -0/+3That is true. Thats the point of 16k and 32k voip. Its something you use in groups to collaborate and communicate. Its great for business environments where you need to make sure you understand fully what is going on.
    
    /b
1980Tim, on 04/15/2008, -1/+21The HD in "HD Radio" actually stands for Hybrid Digital not High Definition.
http://en.wikipedia.org/wiki/HD_Radio
Another example of a company using deceptive marketing to sell you an inferior product.
- briankwest, on 04/15/2008, -1/+4They can't help it stupid people fall for it.
  
  /b
cadmiumpaint, on 04/15/2008, -2/+3If they offered High Def phones, sure i'd be interested...but only if its free. I wouldn't pay a dime to fix what ain't broke. However i haven't had any sort of phone besides a cell phone in over 5 years so i guess i'd never have access to it anyhow
- briankwest, on 04/15/2008, -0/+2They do. The Snom, Polycom, Grandstream and many more support G722 wideband along with a few other codecs that are wideband also.
  
  /b
- mjerris, on 04/15/2008, -0/+4Also, more recent nokia handsets support AMR wideband over voip, the issue is the underlying telephone networks don't support it. With the emergence of voip/mobile convergence, you can expect to see more services like this available to the average consumer.
ErikHarrison, on 04/15/2008, -6/+20STOP MISAPPROPRIATING BANDWIDTH. I can hear my wife bitching just fine on the phone I have now.
- mjerris, on 04/15/2008, -0/+3For what it's worth, the g722 codec uses the same amount of bandwidth for wideband as g711 does for narrow band. On the other hand, it does a better job at transmitting higher frequency ranges of upset spouses or complaining children. The good news is, its not generally available at home, typically more on commercial pbx devices and voip.
twitchster, on 04/15/2008, -7/+1I've played with Higher Definition audio streams, using VOIP and Video Conferencing systems. It's not good. Unless the a new spec filters out background noise, normal conversations become annoying (you hear rustling of paper, chatting of other people in the background, etc). On conference calls the background noise becomes distracting. If you thing people yelling "MUTE! MUTE YOUR PHONE NOW!" is bad now - try it with higher def audio streams.

HD telephony sounds nice, but it introduces issues that have been largely resolved as a result of using lower quality sampling.. In the end it comes down to implementation, of the spec, and the technology.
FuzzyCat, on 04/15/2008, -0/+5
It's all marketing - Even Tom Tom are using the term to try to sell more navigation kit. HD-Traffic.. WTF ....
lambda, on 04/15/2008, -6/+2HD telephone is like HD TV. You don't understand it until you try it.
- astrotrain, on 04/15/2008, -2/+1I understand it, and just don't get it.... .there is more commercials and junk on tv, that I just don't justify paying
  hundreds of dollars to see in HD. Wow... I can see the texture on that Maxipad in that commercial.
  
  Expensive to maintain, if thy break your out of some serious dough because its cheaper for the manufacture to sell you a new one then it is to repair it for you. Which now leads into the issue of E-Dumps of all broken
  HD TVs, that will not just "go away" if we close our eyes.
  
  HD was also responsible for the death of analog TV in Feb 2009. Analog can be received world wide on any TV... now it will be dead. So families who can not afford the converter boxes are now going to be without TV (another government screw up... just like switching the DST ordeal).
  - briankwest, on 04/15/2008, -1/+3I get the impression you have never really seen True HD content, And you can have Digital Content without it being in HD. Thats the point of the switch over is to go digital. HD isn't a requirement.
kymike, on 04/15/2008, -1/+6Why did the lead-in say "Ignore some of the FreeSwitch-promotion"? I read the whole article, and it didn't sound very self-promoting to me...

Anyway, and more on-topic: Screw HD-audio. What I want, more than anything (phone-related) is LOWER LATENCY on my cell phone. I can't stand the delay between one side talking and the other side hearing - I'm guessing the latency is on the order of 100 to 200 milliseconds (AT&T Wireless). It is especially bad when both sides are using cell phones.
- SwK386, on 04/16/2008, -1/+1That latency is due to the digital encoding and jitterbuffering they are doing... the only real way to get rid of it is go back to analog so you can complain about the call quality... the DSP has to wait for a big enuff chuck of audio to encode, then encode it then transmit it, the far end then has to buffer (for jitter) then decode, then send it to the speak for the listener to hear... I'm suprised you even notice 100ms unless you are calling yourself...
  
  eitherway dont look for a solution it anytime soon (oh and BTW VoIP works the same way)
  - kymike, on 04/16/2008, -0/+1Are you the one that dugg me down? That's pretty lame, if so, considering that my comment was pretty neutral and not inflammatory...If not, then never mind ;-)
    
    Regardless: Are you kidding? The latency is blatantly obvious - don't you ever have to say "sorry - go ahead" when you accidentally talk over someone? And again, it's twice as bad when both sides are on cell phones.
    
    I don't care about it as much when making personal calls. The problem, for me, is when making business calls. I'm a consultant, and deal with prospective new clients frequently. For this scenario, that latency can lead to occasionally awkward situations. (It wouldn't be as big of a deal for existing clients that know me already.)
    
    As far as a solution is concerned...100 - 200ms is quite a bit of time, and I would really think that could be cut down considerably somehow, some way. For one thing, I'd bet that the network infrastructure could probably be optimized (cell tower to central office, for example.) Prioritize cell calls over landline calls maybe. Faster processors, maybe. Throw out compatibility with existing systems and start from scratch (new encoding/buffering approaches.) I'm not saying that will ever happen; I'm just saying that I'm not happy with the current latencies.
    
    In any case: Does anyone know if any particular provider or network architecture has lower latencies than the others? I.e., Verizon (CDMA) vs AT&T (GSM)? Could my handset itself be part of the problem (Treo 650 [yes, still] in my case).
analogs, on 04/15/2008, -1/+2I can't imagine anyone getting too excited over increased sound quality on a land line but a cell phone is a whole other can of worms.
- anthm, on 04/15/2008, -0/+1It's not so much the increased quality as the increased frequency range which allows you to better distinguish syllables and pronounced letters.
  like when you are trying to say your email address to someone over the phone.
RealmDown, on 04/15/2008, -2/+4HD = "We can charge heaps more money for it."
mjerris, on 04/15/2008, -0/+5If you want to try this out for yourself, download a free client like x-lite set it for just speex wideband and try calling sip:1616@conference.freeswitch.org with a friend, use a headset, because the comment about background noise is valid. Its one of those things that you need to hear the difference to understand.
tomakun, on 04/15/2008, -2/+4I always cringe when I hear the term "high definition" applied to audio. I'm pretty sure that the term implies something visual (as in the way something is visually "defined"). Although it seems like "HD" is the new buzzword is for anything that is (or the marketing department wants to sell as) higher quality than something else.
- anthm, on 04/15/2008, -0/+3Yes, HD-Telephony is the term given by the industry to describe 16khz audio used in place of 8khz in a telephone. It's actually a higher sampling rate meaning there is more information from your voice so it's a more accurate representation. So it's not a better presentation of the audio it's a more detailed presentation. Such as the difference between a millions of colors tiff image and the same image reduced to a 256 color gif.
- astrotrain, on 04/15/2008, -1/+1HD-_fill-in-the-bank_
  
  The advertising world has gone ape for HD worldly possessions. Well look, its an HD-Toilet, do your business in HiDef. And when your done, shhh... listen you can hear the HiDef Flush.
  
  Just like with the little magnetic car ribbons, there is no more sense behind it, everyone caught on, and is trying to make a buck on the catch phrase.
fxu1989, on 04/15/2008, -2/+6Next to come: HD-Microwave
protogenxl, on 04/15/2008, -0/+6What happened to ISDN lines?
- macslut, on 04/15/2008, -1/+4I Still Don't kNow.
  
  Actually, cable and DSL pretty much killed ISDN.
- anthm, on 04/15/2008, -0/+3We're working on that too actually. An open source ISDN stack that if it was point to point could use the g722 codec which was designed by the ITU to do 16khz audio and take the same bandwidth of a standard 64kbps digital channel.
Woecip, on 04/15/2008, -0/+4So everyone changes to VOIP teles as opposed to POTS lines , which by doing so degrades the voice quality due to the current problems with VOIP. Now they offer HD service to improve the quality they screwed up in the first place? Ugh.
- anthm, on 04/15/2008, -0/+3That's true,
  
  When sending a call to gateway to the PSTN it's pointless to establish a 16khz call.
  If you are going to terminate to another 16khz termination point such as another phone or a conference then it's ideal.
hamdevguru, on 04/15/2008, -0/+3BT have been doing it for a while on some devices: http://bt.custhelp.com/cgi-bin/bt.cfg/php/enduser/ ...
There used to be a more detailed site about it but I can't find it anymore.
dforce, on 04/15/2008, -0/+3The Polycom SIP phones that have 'HD Voice' sound incredible over a hosted PBX - like the person is sitting in the room talking to you
briankwest, on 04/15/2008, -0/+2I'll be demonstrating wideband at Cluecon http://www.cluecon.com

You should check it out.
jakerobinson, on 04/15/2008, -0/+2Shoretel already supports a 16khz wideband codec. 256Kbps!!!! http://www.shoretel.com
- briankwest, on 04/15/2008, -0/+2Must be uncompressed L16 which is really dumb.
  /b
- anthm, on 04/15/2008, -0/+2uncompressed audio at 16khz may be that speed but the ITU standard G722 codec which is freely downloadable uses just 64kbps, the same as standard G711 ulaw or alaw which is the default PSTN and ISDN codec.
bdbr, on 04/15/2008, -0/+3I don't know what was wrong with the term "wideband" - why do they feel the need to change it to HD-telephony?

This is only useful if you have a specific group of people who call each other on a specific set of devices. If they ever call to/from a regular phone, no wideband codec can be used. My company did a trial and it sounded great on those rare occasions that they called each other.

BTW, the GIPS codecs used by Skype support wideband audio. A lot of people like the quality of Skype-to-Skype calls. If your call is to/from a regular phone, the narrow-band G.729 codec will be used.
- briankwest, on 04/15/2008, -0/+4You can Thank Polycom for that they started the HD-Voice in their products.
  
  /b
astrotrain, on 04/15/2008, -1/+1Just go visit the family member or friend instead of spending hundreds of dollars into an HD Phone. Graham Bell is LOL'ing in his grave at this gimmick... sheesh.

** Queue the lame Comcast Phone Commercials now... **
- briankwest, on 04/15/2008, -1/+2You seem to be missing the point. Its one of those you won't fully understand till you hear it.
  
  /b
rxbudian, on 04/15/2008, -0/+1I prefer to have a better quality microphone that captures the person speaking and not the surrounding noise than a better quality audio passing through my ears through the phone in the middle of a traffic jam. I take calls not for enjoyment, if I want to enjoy sound, I stay at home or use a good headphone.
- anthm, on 04/15/2008, -0/+2Yes, the point of all of this is to capture a more detailed audio stream. No matter how nice your mic is, if you are only sampling at 8000 hertz it will drop a great deal of the detail from your voice. We are talking about doing 16000 hertz instead which is twice the sampling rate so there is a higher range of the audio captured into the stream and since less is dropped it makes people sound more clear when they are saying things that can be easily confused like saying the letters M and N.
NSsoccer1, on 04/15/2008, -1/+0My life is in High Definition.
- Leomarth, on 04/15/2008, -0/+2Well, technically the area the size of your thumb at arms length is your "high definition" area. The rest gets kind of fuzzy.
  - GabingtoN, on 04/16/2008, -0/+1Your fail is in High Definition.
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HD-Telephony: Hip or Hype?

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