Well the title says everything, I'll give specifications on in this box ;)
The headset = USB from Logitech \ \ My in ears are 3.5mm 'Jack'.. from Sony
I like the sound of the in ears better(Especially for gaming), but I need a mic for TS..
TeamSpeak (at least version 3) allows you to chose the speaker and microphone interface you want in the options (Playback I guess).
For the other applications, that does not have that setting, you can try to change windows default recording device, and playing device in the sound control panel (are you windows user?)