I have a normal headset and a usb headset. I would like to watch a movie say using vlc with audio output coming through both normal and usb headset. Is there any way to do this. I am using 32bit windows10
Just make sure you connect the PL headset to the audio jack on your computer, and set the settings on the USB one to collect audio from VLC. It's really product-specific, so a general overview might not be what you need.
Probably easier with a physical splitter - they're very cheap and you can buy one along with a converter for USB->PL from eBay/AliExpress.