From the “Review of Web Audio Processing: Use Cases and Requirements”
Need a requirement to provide ways to avoid triggering audio-sensitive
epileptic seizures. The fact that sounds from a variety of sources might
be combined, including script-generated sounds and transformations that
could have unplanned artifacts, mean the final sound output may be less
under the author's control than studio-edited sound. It is important to
find ways to reduce unexpected effects triggering audio-sensitive
epileptic seizures. To some extent this means warning authors to be
careful, but any features we can build into the technology, we should.
Unfortunately this is a new field to me and I don't know all the
specifics, so it will take research (which of course I volunteer to be
involved in, just looking for a placeholder for the issue now). A quick
scan online suggests that certain beat frequencies and reverberance
effects are known sources of problems. A set of user preferences
allowing users to disable or control certain Web application-generated
audio transformations might help with the latter issue.
Surely this belongs on the operating system level, since it could the combination of <audio>, Web Audio API and Flash video running in 3 different browsers that produces the problematic sound?
I have looked for references on the web to this topic that point to information about how such audio stimuli might be characterized as likely to trigger a seizure, but so far have been unable to find any such information.
What seems to be agreed is that in some cases audio does dispose certain epilepsy sufferers towards having a seizure, but that the nature of the stimulus is highly variable. In some cases, for example, the stimulus can be a specific song (http://www.scientificamerican.com/article.cfm?id=musicophobia-when-your-fa)
Between the fact that 1) there's no apparent objective way to characterize an audio signal as epilepsy-inducing or not, and 2) Web Audio can't access the complete. summed audio output of a user's computer, I am not sure there's a way to make concrete progress on this issue.
(In reply to comment #2)
> Between the fact that 1) there's no apparent objective way to characterize an
> audio signal as epilepsy-inducing or not, and 2) Web Audio can't access the
> complete. summed audio output of a user's computer, I am not sure there's a way
> to make concrete progress on this issue.
Good points Joe. I'm going to park this issue for now.
Hearing no objection after a couple of weeks, closing.