This is just fascinating to me. Apparently there is a species of monkey called Campbell’s Monkey and there are 6 different calls or sounds that it makes. Researchers have discovered that by using different combinations of these sounds they can communicate different things to their peers. So for instance… the sound they’ve labeled as “krak” means a leopard approaches, but they can add the suffix -oo to it for krak-oo as a more general “word” for predator when they hear the sounds of a predator but do not see it.
boom boom would mean gather together but boom boom followed by krak-oo krak-oo krak-oo might indicate a tree falling. Hok Hok Hok is the sound made to warn of the presence of crowned eagles. Really fascinating stuff… more research I’m sure is coming.