how is the gate that you put your headphones in called?

Solution
A USB-to-3.5mm jack... which would mean buying a USB sound card as they don't make USB to headphone converters.

Alternatively just buy a USB headset which has a mini sound card built into it and comes with the headphones.
A USB-to-3.5mm jack... which would mean buying a USB sound card as they don't make USB to headphone converters.

Alternatively just buy a USB headset which has a mini sound card built into it and comes with the headphones.
 
Solution