An idea straight out of opera gx (hopefully not patented). Background music or noise for when it gets too quiet. Could have a couple wooshes and woos built in and maybe even allow us to add some of our own?
Also too closely related to this idea would be the music player (as well in opera gx). Both of which are automatically muted if something in the browser is playing. Altho that is integrated with multiple services and would take longer to add. Id say this all could be toggleable ofcourse.