Somebody Please Bring HD Voice to the U.S.
by Leslie Ellis // April 17 2012
Writing about something you have to hear to believe is as vexing, if not more, than writing about what you have to see to believe.
But even that comparison is a start.
Let’s assume that we all lived through the first days of HDTV. (Mine was at the Atlantic City Convention Center, on the boardwalk, in the early ‘90s. The booth was draped in black cloth, to keep the viewing area dark enough.)
If you’re like me, your first reaction to HDTV was something like this: Wow. That’s better than my eyes can see.(And at the time, I had 20/10 vision.)
The same is true — and then some — for HD voice. It’s better than your ears can hear, even if you didn’t spend too many cumulative hours in front of the Marshall stacks at this-or-that concert. It sounds like the difference between any airline’s complimentary earbuds, and Bose-grade earphones.
Trust me: You want this. It’s that good.
Why so good? The lingo of HD voice is a little bit bandwidth (“wideband” plays here), and a little bit codec (a tech sniglet for “coder/decoder;” the big one is G.722.)
Bandwidth plus codec equals better audio resolution — just like it did for video resolution, in HDTV.
How much bandwidth? Not much, in relative terms: 7 kilohertz (kHz) for HD audio – compared to 3 MHz or more for one stream of HD video. (Refresher: To get to a “mega” from a “kilo,” add three zeroes.) But in voice terms, it’s nearly a doubling: Your phone today likely uses about 4 kHz for your conversations.
Physiologically, by spectrally stretching into higher and lower frequencies, the human ear can hear more. Going spectrally higher (to 7 kHz, from 4 kHz today) makes consonants sound clearer; dipping lower in the band (down to around 50 Hz, from 300 Hz on today’s phones) adds depth and clarity.
All of this brings to mind one of comedian StevenWright’s classic observations: “I got a walkie-talkie. It doesn’t work.”
The good news is, with HD voice, even if only one phone is tricked out with an HD codec, call quality still improves. But the technology really sings with dual-codecs — one in your phone and one in mine. No more “I’m sorry, can you repeat that?” No more “say again?”
Six years ago, HD voice launched in parts of Europe, and especially France. Here in Colorado, the summer concert season is about to start (read: more potential hearing loss.) Hint, hint…
This column originally appeared in the Platforms section of Multichannel News.