It seems a physicist at the University of Washington has put together a simulation of "the sound of the big bang." (Although it should be noted that he had to shift the frequency up by a very large amount in order for it to be audible to the human ear.) The original (somewhat technically detailed) article on the subject, together with a link to the .wav file, can be found here. Here's a brief quote:
Theoretical studies have shown that as the early universe expanded, sound waves propagated through the dense medium that closed back on itself, so that the hypersphere of the universe rang like a bell. The detailed frequency spectrum of the sound waves that permeated the primordial universe, literally the sounds of the Big Bang, depends on details such as the expansion rate, the energy balance, and the matter density of the universe at the early age of 300,000 years.
I don't know that there's any great scientific usefulness in it, but I have to admit, it's kind of an eerie/cool sound.