https://www.bleepingcomputer.com/news/microsoft/microsoft-investigating-new-windows-10-high-pitched-noise-issue/

Microsoft is working on resolving a high-pitched noise issue Windows 10 users hear when using some 5.1 audio configurations after applying recently released cumulative updates.

"After installing KB5000842 or later updates, 5.1 Dolby Digital audio may play containing a high-pitched noise or squeak in certain apps when using certain audio devices and Windows settings," Microsoft explains on the Windows 10 Health Dashboard.