Turtle Beach headphones Input not showing up

[netherracksame]

I recently got a pair of Turtle Beach headphones with a mic that can be adjusted into three positions: one by my face to turn the mic on and two positions to mute it. While the headphones are correctly set as the output device, I can't find an option for the headphones' input device. Setting it as default doesn't work, and there's no other visible option.

Can anyone help me resolve this issue?