- From: David MacDonald <befree@magma.ca>
- Date: Tue, 2 Nov 2004 22:20:04 -0500
- To: <w3c-wai-gl@w3.org>
- Message-Id: <200411030320.iA33K4ZG019048@mail3.magma.ca>
Guideline 1.4 Make it easy to distinguish foreground information from background images or sounds. ... Level 3 Success Criteria for Guideline 1.4 . - Audio content does not contain background sounds or the background sounds are at least 20 decibels lower than the foreground audio content, with the exception of occasional sound effects. [V] Note: A 20 decibel difference in sound level is roughly 4 times quieter (or louder). Background sound that meets this requirement will be approximately four times (4x) quieter than the foreground audio content. Guideline 1.4 (visual-audio-contrast) Issues Hi All I had an action item to provide recommendations on 1.4 based on the open issues and my research. Until we come up with an alga rhythm much of this guideline is up in the air. One person recommended an extensive research study. (Bug#996) Ideally that would be a good idea. I wouldn't mind joining some people but it would require a team to conduct the size of study he is suggesting in order to get a statistically meaningful sample size. He also suggests it would require a statistician. Apart from that elephant, I've closed a lot of bugs and I have a couple of suggestions that might help based on my recent discussions with people in the audiology field. Suggested additions are in the <new></new> brackets. Who Benefits from Guideline 1.4 (Informative) Individuals with low vision can easily read characters in the content even if they don't have the wide field of view or full range of color perception used by fully sighted persons to separate text from background images. <new> This will also aid comprehension for individuals with cognitive disabilities who benefit from easy discernment of text. Visual contrast also helps individuals with hearing impairments who are aided by clear visual representation of information </new> Add a note to the bottom of the informative section as follows: <new>Note: Audio Contrast is also known as "signal to noise ratio" by audiologists, where "signal" refers to the foreground and "noise" refers to the background.</new> Cheers David MacDonald ------------------------------------------ Access empowers people... .Barriers disable them. www.eramp.com
Received on Wednesday, 3 November 2004 03:20:10 UTC