Hey there! It sounds like you're facing a tricky situation with audio persisting in Firefox for iOS, even when you don't have any tabs open. This can indeed be a bit annoying. To tackle this, try clearing your browser's cache and cookies. Sometimes, these bits of data can cause unexpected behavior. If that doesn't do the trick, let's give the good ol' restart a shot. Close the Firefox app completely and then reopen it. This usually helps reset things. If the issue persists, consider uninstalling and reinstalling the app. It might seem like a cliché, but it often helps resolve stubborn bugs.