This is the sound that myself and others agree is what you hear when a loud noise makes your ears ring. Why this particular frequency? i don't know. It's just a simple generated tone--you can loop it to make it longer.
Bach's "overture (suite) no. 2 in b minor bwv 1067: vii. Badinerie" converted into an 8-bit, chip-tune ringtone. It makes a perfect loop, so it is great for call ring-tone.