Diagnosis
This is coil whine from the monitor's internal power supply or circuitry, often triggered by a specific refresh rate or brightness level.
How to Fix It
Change the refresh rate. In Windows display settings, try switching from 144Hz to 120Hz. If the noise stops, the power circuitry is resonant at 144Hz. You can also try slightly adjusting the brightness up or down from its current level.
If That Didn't Work
Disable any variable refresh rate technology (AMD FreeSync) in the monitor's OSD under 'Game Settings'. The constant clock adjustment for VRR can sometimes induce whine.
Heads Up
This noise is generally harmless but can be persistent. If it's loud and occurs at all settings, it may indicate a component fault where contacting support is your next step.