This is a bit off topic but my Kindle Touch makes a high pitched squeal every time the E-Ink display updates (It sounds sort of like a muffled hard drive seekin

This is a bit off topic but my Kindle Touch makes a high pitched squeal every time the E-Ink display updates (It sounds sort of like a muffled hard drive seeking). It's only possible to notice when it's really really quiet, and it might be high enough that adults can't hear it. I've been wondering if this is specifically a Kindle thing or an E-ink thing in general, and if the screen didn't refresh the noise might become extremely irritating if used in a quiet setting.