1. Bilabial trill
What? When you roll an r, that’s a trill. What’s a bilabial trill? When you “roll” a b or a p.
Who does that? Speakers of a few languages in Africa (Kom, Ngwe), Indonesia and New Guinea (Kele, Nias, Titan), the Pacific Islands (Unua), and South America (Pirahã, Wari’).
When did I do that? Last time you blew a raspberry.
2. Pharyngeal fricative
What? Fricatives are sounds that buzz or hiss, like “s,” “z,” “f,” and “v.” Pharyngeal means you make the sound in your pharynx, which is deep in your throat.
Who does that? Lots of people. Speakers of Arabic, Hebrew, and Somali, but also speakers of some European languages (Galician, Maltese) and various North American indigenous languages.
When did I do that? More than likely sometime when you were trying to clear your throat or cough up a popcorn hull.
When I was studying Arabic, I was taught to make a pharyngeal fricative (the voiceless one) by making the sound you make to clean your glasses by breathing on them. It worked pretty well.