My brother is playing a game with his usb headset and I want to listen in. I have regular headphones that you plug into a headphone jack and usb headphones. We can't get either to work. (We do not have and do not want to purchase a splitter.)
Its not going to work easily thats for sure. USB heaphones are fed digital data which the soundcard inside the headphones turns into audio.
Your regular headphones are sent audio straight from the motherbds sound card.