Go to any country where you don’t speak the language, and you will obviously have some trouble communicating. You may have a little help, with languages sharing common roots and similar words, but without background knowledge it’s probably time to start pointing, grunting, and apologizing in your own language as best as you can get across.

But there’s one word that appears to have a “universal” meaning across many different languages. Say it, and you will likely be understood despite language barriers, prompting linguists to investigate further.

Word sounds, whatever language you are talking in, are generally assumed to not be connected to the meaning that word conveys. There are many different possible sounds available in languages, and across languages without common roots there is little crossover where words with the same meaning have similar sounds to them. The word dog, for example, used in one study, is “Hund” in German, “chien” in French, and “inu” in Japanese.

But one word appears to buck this trend, with the linguists finding it may be universal. That word is “huh”. Huh?

“A word like Huh? – used as a repair initiator when, for example, one has not clearly heard what someone just said – is found in roughly the same form and function in spoken languages across the globe,” one team of linguists from the Max Planck Institute for Psycholinguistics explained in the Ig Nobel Prize-winning study, published in PLOS ONE in 2013, adding “the similarities in form and function of this interjection across languages are much greater than expected by chance.”

The team looked at the word across 31 languages, finding that it had universal aspects to how it is spoken and understood. However, they went on to focus on 10 languages from five continents, taking a closer look at how the word is used, pairing up conversation partners in order to study its use.

“In all languages investigated, it is a monosyllable with at most a glottal onset consonant, an unrounded low front central vowel, and questioning intonation,” the team explains. While the word sounds slightly different in all languages, it shares these characteristics. 

The team discussed a few ideas why this word may be universal, including that it is an innate grunt produced by all humans, and that it resulted from convergent evolution of languages, sort of like how the crab shape evolves a lot in nature. 

The team reasoned that if it were simply a sound humans made when confused (like how we cry out in pain) it would not be acquired and perfected during normal linguistic learning in childhood, but would appear before other words are picked up. Instead they favored the convergent evolution hypothesis, explaining that inability to hear other people talk or understand their meaning is a universal phenomenon in conversation, and that the word may have evolved as a short prompt to make a conversational partner repeat themselves or explain themselves better.

“Given these pressures of turn-taking and formulation in conversation, a signal that indicates trouble should be minimal and easy to deploy. At the same time, given the communicative importance of indicating trouble (which if not solved might derail the conversation), such a signal should also clearly indicate a knowledge deficit and push for a response,” the team concludes. “These requirements are met rather precisely in the combination of minimal effort and questioning prosody that characterises the [repair] interjection across languages.”