That sound that’s made when you swallow – while taking – and then click your tongue against your mouth while also, possibly smacking your lips. This may not be a good description, but basically everyone on YouTube seems to do this and it’s possibly the most torturous thing I’ve ever had to endure. I guess the best example I can give is Because Science’s Kyle mostly in his live episodes. He does this thing just about every 5 seconds. -_-
I don’t really have any problem with most real people because I have agoraphobia, so my only exposure to annoying sounds comes from YouTube.