From the Atlantic:
“’Huh?’ may be a non-prototypical word, but it is a word,” they wrote. After all, it requires being spelled and conforms to the general principles of each language.
For the study, linguists Mark Dingemanse, Francisco Torreira, and Nick Enfield compiled information from 31 different languages, and compared the prevalence and use of “huh”-like words.
“Huh” was unlike other question words in those languages—it was always one syllable, consisting of a short vowel sometimes preceded by a glottal consonant sound (one made deep in your throat). It also almost always had a rising pitch, the intonation most languages use for questions. “What,” by contrast, took a number of different phonetic and structural forms across the languages, like “que” in Spanish, or, gloriously, “wat,” in the Netherlands.