sound197

I found this sound on an old CD-R, burned way back in 2004. This file had no other context than the actual sound itself, which I found a little weird. The first noticeable thing is the metronome ticking, at which sounds like 120 BPM, 4/4 time signature, with first beat exaggerated. The other thing that you are hearing is DTMF (dual tone multi-frequency) tones, the tones used with digital telephones and cellular calling. To me, the sequence of tones sounds like 1, 2, 3, 4, 5, 6, 7, 8, 9, #, 0, and *.

The only logical explanation that I can come up with based on the context is that this file was some kind of test file created by a phone company, and includes a metronome ticking in the background to prevent any accidental phone phreaking. The tones were likely generated by a blue box.

The metronome ticking could have been generated with a metronome program on a computer, or, played back via synthesizer.

Finally, if you listen closely, after every tone, a quiet tick like sound can be heard. I couldn't figure out what it is or what it could be, but maybe you can find out. And who knows, someone could've just made this with their computer, either to be funny, or they were practicing combining audio files together.