I've had no idea, but now that I saw this it makes sense since sound is nothing but a vibration so if hard disk plates can vibrate so precisely they can indeed produce a sound and serve as speakers.

That's what basically happens in any normal speakers anyway, except that it's not the plates, but thin membranes vibrating.

Very cool stuff. I have one old disk, maybe I could try this sometime.

COOOL.
The guide is not too good tho.. on how to create your own. I may try this though. I do have a few hard drives that are dead . I can not imagine the sound is great..and also the life expectancy I would guess is pretty low.
Be cooler if I could put NUX on the disk before I do so!