I have had this noise coming from my computer and I am not sure what it is. It is an HP Envy 700-249 with an Intel i7 4770, nVidia gt 635, and the PSU is 460W that came with the computer (internal ATX 460W) It was making the sound before and I thought dust may be the issue so I cleaned it but it changed nothing.
Link to mp3 of the noise (closeup audio with iphone [quality may be a little bad]): http://vocaroo.com/i/s0aSSzr91f7p
Note: The sound isn't always on, it sort of turns on and off either very often or not at all sometimes
It seems to have gotten worse? Here's another audio clip: http://vocaroo.com/i/s1roaRrZQcNi
Edited by llama drama, 09 November 2015 - 10:49 PM.