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Click the link in the description to start learning a new language today with Babbel. [ ♪INTRO ]. On every continent besides Antarctica, you can find groups of people who communicate by whistling.

And not just, like, to get someone's attention or say, “I'm over here!” These are full-blown languages. For a long time, all sorts of researchers have been interested in this form of communication, which seems to blur the lines between language and music. And recently, research by neuroscientists has shown that the way language works in the brain… is not exactly what we thought.

Although whistled languages emerged separately all over the world, they tend to have some key features in common. Like, they usually exist among groups of people living in spread-out communities who need to communicate over long distances. Because, conveniently, the high pitch and volume of a whistle can travel a lot farther than regular speech — up to 10 kilometers away, in some cases.

And not only do whistles travel farther, they also stand out more against the sounds of rivers, wind, and animal calls. So they can be a great communication tool in rugged environments. Like, in the mountains of Oaxaca, Mexico, police actually used their whistled language for years before they switched to walkie-talkies.

But these languages don't just replace speech — in many cases, whistled languages are adaptations of the local spoken language. And that's one of the things that makes them so interesting to neuroscientists — because, oddly, even though they're two versions of the same language, the brain doesn't process them the same way. Two whistled languages that have been studied in depth are Silbo, which is based on Spanish and found in the Canary Islands, and a Turkish-based language found in the mountains of Turkey.

Here's a sample of Silbo. [♪Silbo whistle noise]. And here's a sample of the Turkish-based language. [♪Tarkish-based whistle noise]. They both imitate the intonations and stresses of speech, which can easily be reproduced in whistles.

Meanwhile, the things that can't be imitated, like vowels and consonants, get translated into cues like rising and falling pitches or different tone lengths. And the fact that they're derived from speech means that these languages are just as rich and complex as spoken language, so speakers can have fluent, nuanced conversations in either one. But internally, the brain is actually doing something different depending on which language is being used.

In general, the left hemisphere of the brain does a lot of the heavy lifting when it comes to processing speech, so spoken language has traditionally been thought of as a left-brained skill. But whistled languages paint a more complicated picture. Because they involve the right hemisphere, too.

Researchers learned this during a 2015 experiment that studied the comprehension of spoken and whistled language in the people of northeastern Turkey. They used a technique called dichotic listening, which is a way of identifying asymmetries in the brain, based on how people register sounds played simultaneously in each ear. In general, sound signals that have to travel farther within the brain to reach the area where they get processed register slightly slower than others.

So even though the sounds are played simultaneously, there will be a small difference in the arrival time between the sound from one ear and the sound from the other. But since the signals come so close together, people typically only register the sound that arrives first. It gets a little confusing here because the brain isn't wired how you might expect:.

Signals from the left side of your body often go to the right side of the brain, and vice versa. Including sounds. So, when a dichotic listening task uses speech sounds, people usually hear what's played on the right side, since the right ear has more of a direct path to the language areas on the left side.

And that's exactly what the researchers found in this study too. As 31 whistle-speakers listened to sounds from spoken Turkish, they identified the ones from their right ear more frequently. But that wasn't the case with whistled language.

When the same participants listened to whistled speech, they identified the sounds from their left and right ears about equally. And that result suggests that language processing may not be inherently asymmetrical. It's just that, by focusing only on one kind of language for so long (the spoken kind) we seem to have formed ideas about language processing that were overly simple.

In reality, the reason language has traditionally been labeled as “left-brained” may have more to do with what we're hearing than the way we're wired. And it makes sense: The left side of the brain processes information that's received on relatively short time scales. And in spoken language, lots of cues come in on short time scales, like the rhythm of syllables or the transitions between sounds, so it's mostly processed on the left side.

But in whistled speech, a lot of that information gets coded into musical cues like pitch and melody, which have a longer cadence. And the left side of the brain doesn't deal with that — the right side does. That likely explains why whistle-speakers use both sides of their brain to process whistled language.

Not only does this tell us that language comprehension isn't strictly a left-brained activity, it highlights the fact that spoken language isn't just a string of syllables. It consists of all sorts of different cues — and certain parts of the brain may be more or less involved in parsing them, depending on what those cues are. It also highlights the incredibly diverse ways that we use language to transmit ideas between people.

If you want to get better at using other languages to exchange ideas and broaden your horizons, you don't have to wait. You could try out Babbel, an app designed to teach you a language and get you using it fast. It takes a lot of time and commitment to learn a new language, but with Babbel, you'll start putting your skills into practice within hours.

Babbel offers 14 languages, including Spanish, French, and German, and it's designed to guide you through the vocab and grammar skills you need to get by in practical situations. You can do it all in bite-sized lessons, just 10 to 15 minutes at a time. So if learning a new language has been on your bucket list, you can start now.

As a SciShow viewer, you'll get 50% off a six-month subscription if you click the link in the description. And as always, thanks for watching SciShow Psych. [♪ OUTRO ].