Onomatopoeia are the "sound words" that are all around us, and it's funny how they work differently in other languages. The word "boo" would be interpreted by native English speakers as expressing disapproval for something, or with an exclamation point ("boo!"), a word meant to scare someone. But in Japanese, the same sound (buu) is the "oink" sound a pig makes, or depending on intonation and the length of the vowel, the sound of flatulence. Once you've lived in Japan for a few years, you start to accept the Japanese sounds as reasonable representations of what we all hear, like nyan nyan for a cat, wan wan for a dog or kokekokko (roughly, koh-keh-KOH!-koh) for a rooster. And then you go to your home country to visit your family and you make some of these bizarre sounds around native English speakers, and they look at you like you're totally crazy.