Test tones are normally used by audio engineers to test the quality of audio hardware or the acoustics of a room. Used creatively, they can also make excellent instrumental samples and you’ll find them appearing on countless DJ ‘battle break’ records, usually at the end of the record on a continuous loop.
Try adding the following effects and scratching with them for some crazy sounds: Ring Modulator, Lo-Fi, Transpose Stretch, Formant Filter, Flanger or Filter LFO. Combine a few of these at once for some real madness!
Listen / Download (click ‘Freesound’ link for download):