Turn off all your extensions. See if the browser stops with the sound. If yes, great! Turn on one extension at at a time, seeing each time if the sound comes back. When it does, that’s the extension having issues…
If turning off all extensions and the sound still persists the only thing to try is to uninstall brave, possibly also deleting your app data also, and reinstalling brave… basically because no clue as to why you’ve got this error sound unless it was a faulty extension…