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re:audio contrast

From: David MacDonald <befree@magma.ca>
Date: Mon, 1 Nov 2004 17:29:20 -0500
Message-Id: <200411012229.iA1MTPk6012690@mail1.magma.ca>
To: <w3c-wai-gl@w3.org>
Joe writes 
>>>>I want hard proof that this is a true accessibility issue that can 
>actually be remedied using today's technology on *Web sites*.
I think Gaudette University the credibility to provide recommendations to
us. I think we will be in dire straits if we stop listening to our
accessibility partners who represent large groups of people with
disabilities. As an action Item I was asked to make examples, I posted them
at http://www.eramp.com/david/audio_contrast.htm 
>>It's completely bogus. Decibels are measured on a logarithmic scale. A 
>>convenient multiple of 10, like "20 dB," is obviously a random choice. In 
>>fact, this entire guideline was pulled out of thin air.
When I first took on the action item to examine Guideline 1.5, I thought the
20 db numbers were arbitrary too, but after spending a day with recording
gear, an afternoon with a forensic audio engineer for the RCMP, and a few
hours dusting of my university Logarithmic math skills, I see that they are
not arbitrary. Hmmm, I never thought those university "weeder" courses would
be any use.
>>>You can't be dictating to authors what their sound mix must be. 
I have trouble understanding why we wouldn't have anything to say about
this. Visual contrast is an issue for low vision people, and we make
recommendations about that. Advocates for people with hearing loss tell us
this is an issue for them. Why should we be prejudiced against the hard of
hearing community by ignoring their needs in the guidelines? Nor do I think
of Success Criteria level 3 as dictating.
>>>It represents an unreal and mythical concept ["audio contrast"], rather
like "unicorn."
The last time I was at a rock concert I didn't exactly talk about deep
philosophy there. I couldn't even understand a person who was saying their
name to me. The foreground (the voice) was not loud enough above the
background (the music). I can only imagine been a person with hearing loss,
having to go through life trying to make out what people are saying above
noisy backgrounds. A friend who is hard of hearing told me that background
noise drives him crazy and prevents comprehension of the person speaking. I
believe that makes it an accessibility issue. 
>>Well, that's great, really-- somehow encoding foreground and background 
>>signals on Web streams. I'm sure iTunes version 5.0 will handle that 
>>nicely. But then, it'll probably also ship with the iPod Telepathy Plug-in

>>to eliminate sound altogether. But what planet are we *really* living on
Actually this would not be that difficult to do. I worked in recording
studios in New York City for 5 years before I became disabled. Movies and
commercials record the foreground (voice) separately from the background
(music, street noise etc). When I was shooting a movie for Paramount, we had
to stop every time a plane went overhead so that we could get a clean
foreground. They only mix them during the last phase of production. It would
not be hard to ship these signals separately and give media devices control
of that. 
But because this last issue is outside the scope of our work on this list, I
would be glad to talk about this somewhere else.how about at a rock concert.


David MacDonald



Access empowers people...
         .Barriers disable them.



Received on Monday, 1 November 2004 22:29:33 UTC

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