I've tested my headphones on an LE OLED and a 512 GB OLED and while it was present on both to the same degree, it was very quiet to the point of me questioning if it was even there. It is only really noticeable in a quiet room. It is not at all noticeable when game audio is playing, but is most prevalent in the menu of SteamOS. Some audio recordings I've heard makes it sounds like some of you are getting a haircut while wearing headphones, and I cannot get my phone's microphone to pick up the sound at all.