Of course, gravitational waves aren't actually sounds — this is just an analogy we use to represent them in an easy-to-understand way. In particular, the human ear isn’t a gravitational wave detector! But what we can do is take the waveforms that we simulate — the actual signal that our instruments plan to measure — and "encode" it as a sound. The sound so generated gives us a very accurate picture of how the system's components behave during its evolution.

Interestingly, for many astrophysical sources of interest, the frequencies at which the gravitational waves are generated are identical to those which the human ear is sensitive to. This means that we can take the functions which represent gravitational waves and simply run it through a sound generator to produce an audio "picture" of what that source is doing. Other sources typically radiated at far lower frequencies; to represent them as sounds, we need to shift the frequencies up to the human-audible range. (This is very similar to the way that astronomers take information from x-ray images and convert different x-ray energies to colors. Such "false colors" allow us to understand and visualize the radiation coming off such sources even though our eyes have no sensitivity to x-rays.)

The following sound files are simulations of gravitational waves emitted by a coalescing binary black-hole system.

spin parameter = 0.998, mass ratio = 10,000