The “unknown” is the key word. You can assume the sounds are working for most users, but I indeed saw several of these topics about Avast sounds not working.

I can’t think about something else in Avast’s area, besides suggesting uninstalling your sound drivers, then reboot and install the latest ones (even if the current driver’s version you have is the latest, the first uninstall could “release” the glitch).

After the uninstall and reboot, and before reinstalling the sound drivers again (from a fresh download), while still with the default Windows drivers you might want to check Avast sounds when the database is updated.

Changing some settings in your sound drivers might be an additional test (AC’97, SPDIF, digital output, playback device…).

Of course, I have no way to assure you that all or any of those changes and tests might actually solve the sound problem in Avast. I’m “throwing” ideas by now with this issue.

I guess the “work” or tests you might be willing to perform depend on how much you really need to solve this issue.

In any case, whether success or fail, please report back here so it could help others too.