W3C home > Mailing lists > Public > w3c-wai-gl@w3.org > April to June 2007

RE: Audio background amendment

From: Sean Hayes <Sean.Hayes@microsoft.com>
Date: Fri, 4 May 2007 23:12:48 +0100
To: David MacDonald <befree@magma.ca>, 'Gregg Vanderheiden' <gv@trace.wisc.edu>, "w3c-wai-gl@w3.org" <w3c-wai-gl@w3.org>
Message-ID: <7261AC2A5F73904CA41773C8F00813FF21FB65C6@EA-EXMSG-C309.europe.corp.microsoft.com>
Just wanted to point out  that, at least according to CSS, a volume setting of 0 is not the same as silent:

Volume refers to the median volume of the waveform. In other words, a highly inflected voice at a volume of 50 might peak well above that. The overall values are likely to be human adjustable for comfort, for example with a physical volume control (which would increase both the 0 and 100 values proportionately); what this property does is adjust the dynamic range.
Values have the following meanings:
<number> <http://www.w3.org/TR/REC-CSS2/syndata.html#value-def-number>
Any number between '0' and '100'. '0' represents the minimum audible volume level and 100 corresponds to the maximum comfortable level.
Percentage values are calculated relative to the inherited value, and are then clipped to the range '0' to '100'.
No sound at all. The value '0' does not mean the same as 'silent'.

Sean Hayes
Standards and Policy Team
Corporate Accessibility Group
  mob +44 7977 455002
  office +44 117 9719730

From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf Of David MacDonald
Sent: 04 May 2007 15:53
To: 'Gregg Vanderheiden'; w3c-wai-gl@w3.org
Subject: RE: Audio background amendment

Oops missed a word

The current intent is:

Individuals who use screen reading software can find it hard to understand the speech output if there is other audio playing at the same time. This difficulty is exacerbated when the screen reader's speech output is software based (as most are today) and is controlled via the same volume control as the sound. <add>Therefore, it is important that the user be able to turn off the background sound.</add>

<add>Note: Having control of the volume includes being able to reduce its volume completely. </add>

access empowers people...
        ...barriers disable them...

From: Gregg Vanderheiden [mailto:gv@trace.wisc.edu]
Sent: Friday, May 04, 2007 12:36 AM
To: 'David MacDonald'; w3c-wai-gl@w3.org
Subject: RE: Audio background amendment


Do we need to include

" control the audio volume (including 0) which is ..... "          ?

Kind of awkward but...

I think maybe we don't need to because I've never seen anything that claimed to have volume control that you can't set to zero.  I'm sure there is one but I THINK we could just put this in HTM.

Other people's thoughts?

 -- ------------------------------
Gregg C Vanderheiden Ph.D.

From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf Of David MacDonald
Sent: Thursday, May 03, 2007 5:46 PM
To: w3c-wai-gl@w3.org
Subject: Audio background amendment
A follow up to one of my comments on the Survey that was tabled. http://www..w3.org/2002/09/wbs/35422/SimplifiedIntroAndConformance/results#xintroedi

I think the language of 1.4.2 needs an adjustment. Or it needs to be fixed in the intent.

<current SC 1.4.2>or a mechanism is available to control audio volume which ...</current SC 1.4.2>

An example. Some authors might say the user has "control" if they can only adjust the volume a bit... which would defeat the purpose of the SC and let them have distracting background. Let's add to the Intent... "Control means that the volume can be reduced to zero DB"

David MacDonald
....access empowers people...
                   ...barriers disable them...

Received on Friday, 4 May 2007 22:13:54 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 20:32:37 UTC