I own several LifeCams (HD-3000 not VX, HD-6000, Cinema and Studio) and do not have any noticeable hum on any of them. My logitech c920 has always had worse quality mic audio by comparison but no hum either. I tested with variable mic sensitivity levels
and clearly picked up the TV audio from the other end of my house at the highest levels. Maybe there is an issue with quality control and shielding your level of EMI, newer revisions of the hardware or the drivers themselves.
You can try these older drivers that I have hosted that resolve dark issues with several LifeCams. I have no idea if they addressed all the issues in the latest releases of the drivers but these tend to be the most stable. Maybe they will address your hum
issue. The LifeCam software with overlays should not be used on Windows 10. Either drivers issued by Windows Update or the generic UVC USB Video device/USB Audio device drivers should be used on Windows 10. You can also try changing any automatic video settings
in the driver. There is always a possibility that one of those features are creating resource/latency issues generating your issue.
Excerpt from one of my other posts on camera issues:
These drivers are compatible with:
HD-3000, HD-5000, HD-5001, HD-6000, Cinema, Studio, and Microsoft-based (not Intel) *Surface Pro Front and Rear cameras (*64-bit only).
LifeCam 4.25.532.0 64-bit \[pcdust.com\]
LifeCam 4.25.532.0 32-bit \[pcdust.com\]
Visual guidance on how to properly update/downgrade to these drivers.