sound of a stellar mass spiralling into a spinning black hole
wav audio file - theoretically derived
This particular example is actually below the frequency range of human hearing, so had to be transposed up to our own range. But many of these events do occur directly within our hearing range, and in principle, they could be heard directly (say by their effect on a resonant metal bar) .. you'd just have to amplify them a billion trillion times or so ..
(the technical challenges of doing this are really tremendous ..
Well, as they say .. 'Gravity wave astronomy .. love it or leave it' -