DIAGNOSIS This is coil whine from the monitor's internal power supply or backlight inverter. It is a physical characteristic of some units and varies with screen brightness and refresh rate.
FIX Lower the monitor's brightness from the OSD (Image > Brightness). Set it to 60 or below. This reduces electrical load. Next, change the refresh rate. In Windows display settings, switch from 175Hz to 144Hz. Lower refresh rates often reduce or eliminate the whine.
IF THAT DIDN'T WORK The whine may be exacerbated by a specific GameVisual mode. In the OSD, under Image > GameVisual, switch from Racing or Cinema mode to sRGB or FPS Mode. These modes use different default brightness/contrast profiles.
HEADS UP Coil whine is not a defect covered under warranty unless exceptionally loud. It is generally harmless and does not indicate impending failure. Environmental temperature can affect its intensity.