Not a recording, but a synthetic whistle sound similar to a boatswain's call (a.k.a bosun whistle), perhaps a wee bit longer than a true call to attention should be. No, I was never in the Navy, and that probably explains it. If you wanted to use it as a ring-tone, you would have to space it out, and I don't know if that means adding a few seconds of silence to the end, or what. Created mathematically in Cool Edit Pro.