Ultrasound as a Linguistic Tool
Ultrasound isn’t just a technique to image fetuses: it’s also helping to preserve dying languages. 473 out of 6,909 living languages are classified as nearly extinct, with a further 3,000 classified as endangered—and it’s crucial to preserve them. Languages not only embody human history and local knowledge, but can also help cognitive scientists study how the brain learns, stores information, and communicates. The key to preservation is documentation, and since many endangered languages are solely spoken, linguists must use recording technology—to record both the sound and the physics behind the sound. MRI, X-Ray, and electric probes have all been tried, but were either inconvenient, too slow to keep up with speech, or too problematic over prolonged periods. Ultrasound, however, has been more successful. An unobtrusive cylindrical probe, held under the chin, is able to image the physical movements of the tongue, documenting some of the fastest sounds in human speech—such as the click consonants of rare African languages. Ultrasound has helped to organise the clicks through their biophysical aspects: the airstream through the mouth, the mouth’s constriction, and articulation. In turn, this has allowed the consonants to be properly classified within the International Phonetic Alphabet—a universal catalogue system of the sounds in the world’s languages—and therefore allowed linguists to study the relationship between sounds, and in turn, better understand people through their languages.