You turn on your PC, start up a particularly taxing program, and then — you hear it. A high-pitched sound emanating from somewhere as if your ears are ringing. You're not going crazy, it's coil whine, and it can come from a number of components in your computer.
Coil whine, as Linus from Techquickie's YouTube channel explains, is a phenomenon found in a lot of technology today, but especially in video cards. It usually occurs when a component is working really hard and begins to vibrate, emitting a high-pitched noise in the process. This is pretty common when playing games, as they tax your video card the most for substantial lengths of time. Additionally, games or other graphic intensive software will tax your video card at different levels, causing a variety of high pitched sounds to occur. If you're playing or working with speakers or certain kinds of headphones, it could become pretty annoying.
What can you do? Well, the unfortunate truth is that once you've got it, you can't really get rid of it. Your best bet is to prevent it in the first place by reading reviews and researching which products tend to have the most coil whine. So before you jump into buying that delicious new video card, be sure to check that it doesn't also come with some distracting coil whine on the side.
Coil Whine as Fast As Possible [YouTube]