a11y and audio

[VeryGoodErotica]

At the moment I can't reach the actual web page that has it (browser can't find idpf.org) but archive.org had it - in 'META-004: Identify accessibility hazards' with respect to audio it mentions:

sound — certain sound patterns, such as ringing and buzzing, can cause seizures.

There does not seem to be an expansion on that, for how to evaluate an audio as to whether or not it may have one of the patters that can be a trigger. I tried searching the web for an evaluation method but did not find one.

Can the doc be updated to give a reference for evaluation?

-=-

Also somewhat related, maybe belongs with WAI for inclusion in their WCAG general techniques and not here - many people (myself included) have an autistic input overload trigger caused by either loud audio or sudden changes in audio volume. I couldn't watch Big Bang Theory because they mixed the laugh track to be really loud compared to the rest of the show, for example, causing an input overload that stressed me.

Using loudness normalization as specified in EBU R128 should be an accessibility technique for audio and video - either by providing the metadata tags or (what I do with audio) applying EBU R128 to the source before lossy encoding, so that it is loudness normalized even if the player doesn't support the metadata tags.

EBU R128 isn't the only scheme but it is the best (ReplayGain for example I believe only takes RMS into consideration which is often inaccurate method) and EBU R128 seems to be gaining a lot of support in the broadcasting industry, including streaming services, so if a user has their volume set what they like when listening to spotify and they then open an ePub with an audio or video that uses EBU R128 the perceived loudness will be where they want it.