I advise Firefox users not to install this poorly written extension.

The "details" section lists 4 feature bullet points and several quotes from positive user reviews. There are no instructions there, or anywhere. If the developer had spent 5 minutes browsing other extensions, he'd know that the details section is for instructions.

There is no settings page. Normally, an extension offers, if nothing else, alternative hotkeys in case, like me, a user is already using the extension's default hotkey.

Using this extension to switch to the tab with sound doesn't work if the tab is in a different Firefox window, making this feature more or less useless.

After trying the extension on several web sites that play sound, I find the extension is sometimes capable of increasing the volume but sometimes has no effect.