Comment Re:Snake oil (Score 1) 213
I've heard this too, though on mine it was only audible when amplified to absurd levels (well, relatively).
Have you ever had a computer that made odd sounds though the speakers when you move the mouse cursor? In my case, it was a very similar sound. Again, quiet - but if you have it loud enough or it's otherwise quiet enough, you can hear it.
I believe this was a Sansa e200r. It didn't have an SD card, but flash memory - in either case still a lot of digital signaling.