DIAGNOSIS This is coil whine from the monitor's internal power supply components, most audible when the refresh rate is high and brightness is not at 100%.
FIX The whine often correlates with refresh rate. In Windows display settings or your GPU control panel, lower the refresh rate from 165Hz to 144Hz or 120Hz. Test at each step. Often, the noise diminishes or disappears at a specific lower refresh rate.
IF THAT DIDN'T WORK Adjust the monitor's brightness. Set the OSD Picture > Brightness to 100. If the whine changes or stops, the issue is in the backlight power circuit. You can then lower brightness via your GPU settings instead of the monitor's OSD.
HEADS UP Coil whine is generally not a sign of impending failure, but a physical characteristic of the components. It can be more noticeable in quiet environments. Samsung may consider excessive coil whine a defect under warranty if demonstrated via video.