[BC] RE: HD Radio -- Folks we have to get it right!

[RRSounds@aol.com]

Please pardon me if I overly paraphrase...

If I'm reading the NPR report correctly, about 16-17% of listeners would 
"discontinue" (their wording) listening to audio coded at 96 kbps with the 
iBiquity codec. The survey says this may, however, be a factor of the audio samples 
used. Maybe a sixth of all listeners just don't like Eric Clapton or The Cars 
(the two "Rock" selections), or think Bizet's "Carmen" is bombastic, I dunno.

"Discontinue" percentage stays roughly the same for the next lower rates, 
(i.e., 64 kbps, 48 kbps) and then spikes for the still lower rates (36 kbps, 24 
kbps). That's where the quote about 48 kbps being no worse than 96 kbps comes 
from.

Coding of Classical and Jazz music styles were most acceptable; Rock and Talk 
did not do so favorably, particularly female voice. :-(

I note that the samples presented to the respondents were unprocessed prior 
to encoding. Since there are as many ways to process music as there are people 
to set it up, I can see why they didn't use processing for this evaluation (is 
there any such thing as "generic processing" for such a survey?).

At any rate, <g> since radio stations that use zero processing will be rare, 
IMHO this survey's relation to real-world broadcasting of anything much beyond 
Classical and Jazz is therefore somewhat tenuous. Works for NPR, however, 
since that is what most of their stations play, even if it does blow off 1/6 of 
the listeners. Then again, they may want to replace Renee Montagne ("Morning 
Edition"), Michele Norris and Melissa Block ("All Things Considered") with more 
codec-friendly male voices if they want to keep ratings during the talk shows.

Additionally there were, at least in this survey, no long-term listening 
tests. In a world where 16 minutes' listening means credit for two quarter-hours 
to Arbitron, I would think that the real severe listener endurance test will 
have to be over longer periods than a song or two.

Just my opinions, of course. No matter my suspicions, I have no idea how much 
better - if at all - AACPlus would do in a similar survey.
I do second Neil Glassman's recommendation to read this report ("Perceptual 
Tests of iBiquity?s HD Coder At Multiple Bit Rates"), and I thank Neil for 
suggesting it. 
<http://euonline.org/pub/iboc/index.html>


Kind Regards,
David Reaves


On Tue, 18 Oct 2005 13:14:23 -0800, Robert Orban <rorban at earthlink.net> 
wrote:
Subject: [BC] RE: HD Radio -- Folks we have to get it right!

<<
At 07:11 AM 10/18/2005, you wrote:
Subject: [BC] RE: HD Radio -- Folks we have to get it right!
To: broadcast at radiolists.net, David at translantech.com
Message-ID: <cd.33199d55.308615ed at aol.com>
Content-Type: text/plain; charset="US-ASCII"


Lest we forget, IBOC FM's 96kbps becomes 48kbps each for two programs when
you go into multiple stereo program mode. Right?

At that point, IBOC's codec quality becomes even more critical (as if it
weren't at 96!)

Can IBOC's codec equal or beat the best AACPlus (and therefore XM) has to
offer?

For a given bitrate, HDC is not quite as good as aacPlusV2. However, I find 
the 48 kbps HDC streams to be of "entertainment quality." That is, the 
artifacts, although certainly audible, do not prevent me from enjoying the 
content. From a business perspective, I don't think that the quality of 48 
kbps HDC is going to drive away the mass audience.

Bob Orban 
>>


David P. Reaves, III
TransLanTech Sound, LLC
Creators of the Award-Winning "Ariane Stereo Audio Leveler"