They're called Laryngeals, and no one really knows how to pronounce them, from what I can tell.
Edit, there are two theories on how to pronounce them:
Rasmussen chose a consonantal realization for *h₃ as a voiced labialized velar fricative [ɣʷ], with a syllabic allophone [ɵ], i.e. a close-mid central rounded vowel. Kümmel instead suggests [ʁ].
Is PIE something like proto-indo-eurasian, or just something to do with pies?
I haven't heard of people screaming about pies in someone's face, so I think it's safe to assume PIE means proto-indo-european :)
and while I'm at it, how do I pronounce *h3?
They're called Laryngeals, and no one really knows how to pronounce them, from what I can tell.
Edit, there are two theories on how to pronounce them: