Cant hear anything from your attachment and recording but, it could be that its your CPU/GPU fan as that is where the power plug is and it could have disturbed something inside? Best thing to do is to open the laptops back cover and pug the laptop in, then check where that noise is exactly coming from, as there are very few moving parts that could make any noise, unless its coming from a audio interference from the speakers which are situated in the bottom left/right corners, check that out. 

andylb said:

@StevenGen & @egydiocoelho could it be Coil Whine?

Yes it could come from the charger transformer or even from the GPU but, when you’re dealing with high end modern PCs, especially the graphics card and power supply, these vibrations can be audible. This is especially true for anyone who’s sensitive to high-frequency noises. In bad cases, you can actually hear the pitch of the coil whine change as the GPU draws more or less power, and the electrical frequency across various components shifts. It might be particularly noticeable when running a 3D game or high-intensity graphics application. Coil whine can be especially noticeable—not to mention frustrating!—on otherwise “silent” PCs, like low-power home theater PCs or gaming PCs with a liquid cooling system.

Coil whine is really nothing to be concerned about. It can be annoying, of course, but it isn’t like a rattling engine or a squeaking wheel—the noise is a byproduct of your PC and graphics card’s normal operation. Your system isn’t losing any performance or longevity because of coil whine.

(Note: if you hear a distinct hissing or high-pitched whistling instead of a buzz or scratch, that might be the altogether different phenomenon known as “capacitor squeal.” This is something to be concerned about, since it indicates a failing component.)

Sadly, there isn’t an easy fix for coil whine, like an updated driver or a Windows setting. It’s a physical property of your graphics card (or any other component you can hear exhibiting the noise). The fixes for the problem, therefore, are going to be physical in nature. You have a few options. Hope this helps cheers.