Originally Posted by Merikus
Thank you all for your replies on this issue. I decided to call customer service to inquire about this, and was told it is a "normal noise added to signify page turning." The agent implied that you could turn it off with a switch on the Kindle, but she wasn't too helpful in specifics.
The agent doesn't have a clue as that noise isn't something they added to signify a page turn. The noise is from the power supply circuitry inside the Kindle. It is in a low power state normally so most things are powered down but when you want to change the page it has to wake up and generate the high (from the point of view of the CPU and other components) voltage necessary to update the eInk screen.
You can't avoid it unfortunately as its just how it works for the Kindle. Other eBook readers with a different design may have the same noise. I'm not sure. It is pretty quiet anyway and I can only hear it if the Kindle is up next to my ear.