I agree that it makes sense to remove this check for <audio> elements:

• The corresponding axe-core rule has been deprecated
• The corresponding Lighthouse audit has been deprecated
• As you mentioned, browsers ignore tracks within audio elements

However, the same is not true for the corresponding rule for <video> elements and browser support is good. I think it still makes sense to encourage captions on videos. The warning can always be ignored in the component using <!-- svelte-ignore a11y-media-has-caption -->.

As a side note, I don't read the warning as suggesting you add an empty <track kind="caption"> -- it's implied that you add a src. We could make the rule require a src as well to make this clear.

Also note that the Svelte tutorial currently has a compiler warning for missing audio captions. Either the rule should not check audio elements or the tutorial should be updated to resolve the warning. This is also a case where it wouldn't make sense to have captions even if audio captions were supported since it's music only, no speech.

The one for video makes a lot more sense than one for audio, since it at least works, but I'd recommend removing it as well, as absolutely overwhelming majority of video content available has no subtitles and will never have any.

Svelte tutorial having invalid fake <track kind="captions"> for video just to make this rule shut up just proves this point.

<!-- svelte-ignore a11y-media-has-caption --> is not much of a solution, as most devs will have no idea it's even a thing, and the warning message doesn't mention that option.

As a side note, I don't read the warning as suggesting you add an empty <track kind="caption"> -- it's implied that you add a src.

Only to someone familiar enough with the track tag to begin with. Just a couple days ago, I created #6034 which quotes a developer who broke his app by including <track kind="caption"> exactly.

FWIW, I like the solution proposed in this issue better than the proposed solution in mine.

I agree...I followed this direction and put a <track kind="captions"/> in my <audio> tag and the app completely broke in iOS 14.4 Safari on the iPhone 12 Pro...filed a bug report with webkit and was able to confirm that removing it completely made the app work again...and I am one of those people who had no idea that I needed a src file, to be honest...it was just something I did to make the warning go away...I get wanting to add this to a video with dialog and visual cues, etc...but don't see the value for tracks, especially instrumentals...I could, of course, be mistaken, as I don't know too much about a11y in general, and am very much willing to learn...but...yeah...seems not super useful for instrumental audio.

I opened a PR to remove the warning for audio elements since it's causing the most issues and browsers don't support it. I made sure to note in the PR that it doesn't completely resolve this issue, since there's still some discussion around removing the warning for video elements as well.

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

just to chime in here, we are building a custom video conferencing app using AWS chime and svelte. We get this warning when we are using the <video> tag as this is required for the AWS chime to inject the video stream. As the stream is live, there won't be any captions/subtitles.
<!-- svelte-ignore a11y-media-has-caption --> was added to suppress the warning albeit not optimal.

More often than not this warning isn't helpful at all. There are numerous reasons why captions wouldn't make sense + some libraries like hls.js set captions dynamically via videoElement.textTracks after parsing the HLS manifest, so there's no <track> tag in the markup.

Even in one of the official tutorials there's a dummy <track> just to silent this warning. Shows how annoying and unhelpful it is most of the time.