Through infancy and childhood, our ability to discern and reproduce the unfamiliar speech sounds of other languages declines. Due to a severe lack of preschool-aged linguists perhaps, precise classification of the click consonants of the N|uu click language of the southern Kalahari has evaded linguistics for nearly 100 years.

Some N|uu clicks are produced by breathing in and creating suction within a cavity formed between the front a back of the tongue. Historically, many linguists have assumed that sound differences they couldn’t discern weren’t real, or at least weren’t consistent in usage. Many distinct click sounds were relegated to a gaping catchall category that included every type of modification ever reported in a click language.

Well, no more! Thanks to the advent of compact ultrasound technologies Cornell researchers now have a record of the very real differences between the N|uu click-consonants. The contraption above is able to broadcast high frequency sound waves and record the wave’s reflective signatures at a sonic frame rate that’s finally fast enough to image the tongue’s placement during the clicks precisely. The findings arrive just in time, too. The moribund N|uu language only has 10 known speakers, and they’re all elders.

Credit: Johanna Brugman, Cornell University, and Bonny Sands, Northern Arizona University