Language sounds are actually audible movements. When we speak, we move our vocal cords, tongue, lips and jaws, often at the same time: it is ballet that produces speech sounds. We have known this general principle for a long time. It is the basis of the work of phoneticians, speech therapists and a number of other specialties dealing with human speech. For example, we know very well which tongue movements make the difference: where and how the tongue closes the oral cavity to produce different consonants, or how it distorts the oral cavity due to vowel differences. But there is still a lot we don’t know.
This year, two fascinating observations have been made about the role of the tongue, seemingly simple but very insightful. One of them has been around for some time, which is that the sides of the tongue play an important supporting role. Producing sounds like s, R in n, for example, is classically described as the front of the tongue making contact or constricting with the bony ridge just behind the teeth (try it). But if you pay close attention, you’ll notice that there’s also something wrong with the sides of your tongue: they’re pressed against the sides of your palate, or your teeth.
It was suspected that this had good mechanical and acoustic reasons: this position provides support for the fine motor action of the center and anterior of the tongue, and also ensures good airflow through the center of the oral cavity. The initial observation was based on English speakers, but if there is already a general mechanical basis, you should be able to observe it in other languages as well. This year, a team of Canadian researchers confirmed this with a highly sophisticated study of tongue movements in speakers of very different languages.
The tongue also experiences weightlessness
The principal investigator of this team continues to lead in the same field. We’ve known for a long time that astronauts have problems controlling movement when they return from space, because they encounter gravity again. But if speech sounds are controlled by fine motor skills of the tongue, wouldn’t we expect problems there too? Astronauts have already reported this anecdotally, but in reality this question has not yet been investigated.
The researchers began working with audio recordings of astronauts immediately before and after a stay in space, and their analysis suggests that immediately after reentry, the average tongue position is significantly lower when speaking. In other words, tongue control becomes accustomed to the absence of gravity (which pulls the tongue slightly down to the ground), and does not adapt immediately when gravity returns. The results are suggestive rather than definitive, but they certainly show that there is much more to our tongues than meets the eye.
