RTTY DEMO 012710.wmv

It sounds quite nice. It is also about the same bitrate as RTTY which was invented in 1922 and is still in use by radio amateurs round the world. Here is what that sounds like ▶ this video Not as musical but quite similar

I don't have the skills of the person who decoded the signal... however, if you get your ham radio license and start playing with the various digital modes, you'll start to recognize the various sounds of different modes. An APRS data packet [1] has a very unique sound. Same with with RTTY [2]. Our brains are really good at pattern matching if they're exposed to a pattern enough times. Obviously, you'd still need a computer to decode those signals, but the "sound" of the signals can give you very good headstart. [1]: link [2]: ▶ this video

Wow it sounds like RTTY (radioteletype): ▶ this video I suppose there are only so many ways to modulate a data signal.