I looks like something that created a Force Field in 'Forbidden Planet' (A mighty film) - but my memory might be playing tricks because it is a while since I have seen it. This is a film you should watch. It is worth at least $1.
Computer speakers or ixxxx speakers - very good quality ones at that :)
But why the hell would there be speakers that did not hook up to anything?
Perhaps it's broadcasting your thoughts to another planet.