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 were 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
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
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
Steven Wright’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.
Stumped by gibberish? Visit Leslie Ellis at