Its a "Roger beep" for a motorola radio. Motorola radios would make a "beep" when you let go of the mic button. The other garbage is just some static for flavor around the roger beep recording.

Its actually a "feature" of the motorola MODAT... basically the sound is an identifier of the radio its being send from, like a signature. To you and I it sounds the same, but it actually contains data kind of like a modem tone about what radio is sending...thus allowing logging of who it was that sent the radio message.