[mythtv-users] CALM Act in US

Brian Wood beww at beww.org
Wed Oct 14 05:13:04 UTC 2009


On Tuesday 13 October 2009 22:40:29 Johnny wrote:
> > But the problem is not solvable, too many factors are involved
>
> One of the good things about the legislation is that they don't
> actually dictate how this is to be done. They use fairly general
> language and give a mandate to the FCC to come up with a good way to
> actually accomplish it. You may be technically right that this problem
> isn't completely solvable. For one there is nothing really being done
> now. So at a minimum there things could improve.
>
> My back ground is in signal processing and I believe there has been a
> lot of advancements recently that will make this largely solvable.
> Some of my colleagues have done a lot of work on modeling and
> processing signals for hearing aids. They have a pretty rich
> understanding of precisely what affects human perception of sound and
> its properties and a good understanding of how to manipulate that in
> precise ways. So I don't think a technically solution is infeasible.
> Also one can assume much of this is deliberate on the advertisers
> part, so the right sort of pressure could discourage them from
> creating this problem in the first place (we can hope right?).

I'm happy to hear from someone familiar with the human side of this problem, 
that's far more complex than the electronic side.

Commercials are produced using many forms of audio processing, usually 
resulting in the audio being more "dense" (for want of a better term). This 
processing makes it even harder to equate "level" with "volume" 
or "loudness", especially when compared to the wide variety and quality of 
program sources, which may or may not have processing of differing types 
applied to the audio.

Much research was done in the 70s by the Orban Company, they made something 
called an "Optimod", initially for AM radio, then FM and finally TV. Back 
then the idea was to be the loudest station on the AM dial of course.

AM Radio actually has an FCC-mandated spec of no more than 100% downward 
modulation, now there's a great law: you're not allowed to reduce the power 
below zero.

I think today's advertisers, or rather the people who produce the ads, go 
beyond making it "loud", they realize that if you irritate the viewer you can 
get negative results (I know it's hard to believe, considering what we see 
(and hear), but I think it's true). Certainly the ads I see on Hulu seem to 
be of a better quality than the ones on the networks or local stations. I 
actually watch most of them.

I guess I just think the government has better things to worry about, this 
sort of thing just distracts the voters from the real issues.

Probably just making it known that the FCC is keeping an eye (ear?) on this, 
along with improved general awareness, will go about as far as we're likely 
to every get.

Perhaps the issue of the hearing impaired viewer will get some attention. 
Years ago I built a simple high-pass filter for my grandfather, his hearing 
rolled off at the high end, so I was able to make it so he could hear the 
consonants without blasting others. Better EQ in TV sets would probably help 
a lot of people.

I still think a human operator is likely to be the best answer, though the 
proverbial "optimum listening environment" is seldom encountered in the real 
world.

TV engineers tend to ignore audio, unless it's not working. An old joke 
was: "Audio? Yeah we'll have that too" 

Maybe we can get an FCC-mandated "Commercial Flag"? Then you could just have 
an adjustable attenuator on the TV set itself for a variable amount of muting 
during commercials.

Myth's commercial flagging is remarkably good, but it's not 100%, nor is it 
likely to ever be, but a flag should be 100%. Of course it might set a bad 
precedent (Broadcast Flag anyone?).

-- 
Brian Wood
beww at beww.org


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