I recently heard about Netflix’s fan event, known as Tudum. But I wasn’t sure how to pronounce that word, nor what it meant. Took me a while, but I eventually found out, from a 2021 article:
Netflix subscribers know the "tudum" sound when they hear it, but maybe not how to spell it until now. The word refers to the famous two-beat sound that can be heard whenever you start a new show or movie on Netflix[…]
So it’s onomatopoeia. I’m still not certain how the vowels are pronounced, but at least now I get the general idea of how the word is supposed to sound.