What word is found in the greatest variety of languages?

Researchers at the Max Planck Institute in Nijmegen, The Netherlands, have researched the word “huh” – “a simple syllable with a low-front central vowel, glottal onset consonant, if any, and questioning intonation” – and found that it exists in widely divergent and typologically different languages such as English, Mandarin, and Siwu (West Africa):
http://www.nytimes.com/2013/11/09/arts/that-syllable-everyone-recognizes.html?_r=0
This may provide evidence for the social origins of language.