While this extension was one of the ones I considered most important, back in the pre-WebExtension days, it hasn't been clear to me in recent years if the WE version is actually doing anything. The GUI is now a lot clearer than in earlier WE versions, but when I tried to set up Firefox 140.0.2 with Noise 3.3.0 to play WAV files for Download Completed, Download Failure (untested), and Download Interrupted, I wasn't getting any sounds. Even tried granting the 2 additional permissions that the Permissions button brings up, and hitting Save, but still no dice.

The most important sound event for me is when "Find in Page" wraps back to the first instance, and thanks to the text underneath the "Read more" in "About this extension" here, I now know that since Firefox 135, this is handled via a native about:config preference, accessibility.typeaheadfind.wrappedSoundURL (can be set to file URLs, or just to "beep"). That one I've confirmed is working.

So if I can't get the download sounds working with this extension, I guess I'll be uninstalling it again. (On its Github page, the author kindly notes that the extension Download Sound by BPS is now an alternative, although sadly, that one doesn't let you customize your sounds.)

UPDATE after Developer response:
Sorry for leaving a review without asking for support first. The reason I did that is that I don't have a lot of time to spend on this, and now that I have the Findbar wrap sound working, others are not a big priority for me.

I tried a few more events (tab events, plus Copy), but no, Noise doesn't seem to ever make any noise (indeed, I've never gotten the WE version to do so). I tried an MP3 file instead of WAVs, but that didn't work either. All the sounds play fine if I use the Play buttons on the Options page, but they never play in response to events. I also tried naming the events (an option I don't really see the point of), but that didn't help either.

I'm aware of the extensions.webextensions.restrictedDomains issue, and I'm not trying to get sounds from restricted sites. I use a few about:config settings, and several other Add-ons / Extensions, but none that I would think would interact with this. I'm on Windows 11.

I tried out the Download Sound extension, and it works as expected (though it unfortunately doesn't seem to be able to play sounds only for for Download Failure, which is my desired setup). I'll try to open a GitHub issue in the future, when I have more time. Thank you for your response.

It is really missing is a default sound included in the extension.

Would love to get this working, DEVELOPER..Help us out, the interface has changed from the older instructions....