Short Wave - Why Babies Babble And What It Can Teach Adults About Language

Episode Date: July 26, 2023

In which we metaphorically enter the UCLA Language Acquisistion Lab's recording castle, guided by linguistics researcher Dr. Megha Sundara. NPR science correspondent Sydney Lupkin temporarily takes over the host chair to talk to Sundara about all things baby babble. Along the way, we learn why babies babble, how that babbling can change with exposure to new languages — and if there are any lessons for adults. Questions about other ways we develop? Email us at [e-mail] and we might answer it in a future episode!See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, shortwavers, Sydney Lepkin in the host's chair for a hot sec today. So a few years ago, I found myself on a train. It was the first time I'd really traveled as an adult and I was in Europe. I was seated across the table from a French woman traveling with her toddler. So his mom and I hid it off and spoke in English for a few hours. Meanwhile, this little boy had a lot to say. I couldn't understand it, but he clearly had opinions about his books, his snacks, maybe how cool it was that his hands were attached to his arms.

And he wanted everybody to know about it. All in what I just assumed was French. So finally, I said to her completely earnestly, hey, so what's he saying? And she paused for a while, and she's like, nothing. He's a baby. So as a reporter, and now the mom of my own chatty baby, I've taken a huge interest in baby babble lately. So I got shortwave to let me make a whole episode about it.

Babies, even when they're very young, are very good at imitating the rhythm and the intonation of the language they're hearing. I called up Dr. Megasunara, a professor of linguistics at UCLA. She studies how babies listen before they start talking and how they eventually learn language. In other words, she's an expert on baby babel. I bet you've heard your baby blow a raspberry. Yes, I have. So that's very common. Then you've got your go-goo and your ooze or a's.

By about 10 months, they're already there. You can recognize the vowels as the vowels they are. You hear consonant vowel combinations. So something like ba-ba-ba-ba. Then you can hear mama also sometimes. Waiting for that one. Still waiting for that one. Still waiting for that one.

To do this research, Megha and her research team bring babies and their parents into their lab. And it's not like any other lab I've heard of. Instead of a drab recording studio, the baby and parent are greeted by a colorful mat, followed by a very quiet, 10 by 10 recording studio Castle. Yes, Castle. There's a research assistant sometimes in there, and then they are quiet toys. And what we do is we give the parents a wireless microphone, which they can clip onto their clothes. And another wireless microphone is on this little baby vest that we put on the baby. And then that's it. We let the baby loose. And we tell the parents to interact with the babies. From that combination, science magic happens.

Megha and her team are able to unearth all sorts of insights into babies babbling. Like the fact that a baby babbling on a train will sound more French if their parents speak French. Today on the show, babbling for all. Why babies do it, why it changes across different languages. and even a lesson or two for us adults. I'm Sydney Leapkin and you're listening to Shortwave from NPR. So, Megha, I'll really just start with a million-dollar question, which is why do babies babble? So researchers can believe that this period of babbling is a period of exploration.

The baby has body parts in the mouth. So they've got lips, they've got a tongue. And fun thing for the babies, anytime. they move these in a certain configuration, they can make sound. I mean, imagine that universe. You move some part of your body and you can immediately get to see what the consequence of that is. You hear it. Turns out even babies that are hearing impaired. So babies who can't hear will also try and vocalize. When you move your mouth, you get sensory feedback. Like your tongue has touched something. How else does that feel? So it's a period of exploration.

which hearing it is just one part of it. A period of exploration that does have some limitations at first. The baza and daas are easy, but... What you will not hear is... S, shas and shas, you won't hear them. They're too hard. Oh, why? Think about how you make a s, okay?

The tongue is not touching anything on your palate. It's just raised to a certain height. There's a small narrow channel you're making and blowing through it. see it's not touching anything that's hard it requires a fine coordination of the exact distance of the tongue against the palate but think about bah or ta you're just taking in your articulators and slamming them against different things so you smack the lips together you get a pa or a ba right if you take your tongue tip and you just raise it up and down you get ta da and that gives you your consonants, the ones that you hear most often. Huh, cool. Okay. And so what do we know about babbling in

different languages? So it turns out babies are very good at imitating the rhythm and the intonation of the language they're hearing. So for instance, a baby babbling, even when they don't make sense, is going to sound like a person speaking that language. Particularly if you've heard a person speaking that language from the next room, but you can't hear the segments, you don't quite understand and what they're saying, but you can kind of tell they're speaking the language. It's because of what we call the prosody, the rhythm and the melody, which is like that language. So that's what babies are really good at. Okay.

So which brings us back to is babies babbling different in different languages. So when babies are very younger, babbling tends not to be very different across different languages. Primarily because there are limits on how much they can move their articulators. Okay? how much control they have over, say, the pitch. So we're talking about like six to seven month olds. Don't look. They don't sound that different.

Okay. Six to seven month old babies who are babbling also don't sound very different whether or not they're hearing. After that time, it turns out babies babbling starts to what we call drift towards the language that they are hearing. Now, this drift seems to happen earlier for the intonation, and the rhythm of the speech. So bilingual households, do they drift toward one or the other?

And how bilingual does bilingual have to be? Does it have to be, you know, someone just visiting, you know, once a month? In bilingual communities, the amount you mix the two languages varies a lot. When everyone's bilingual, there can be high levels of mixing. So like Spanglish, kind of? Like Spanglish, for example. You can have a base sentence in a language. You can just swap out a word.

from another one. So that's what our experiment was. In our experiment, the first 30 minutes the parents spoke in, say, English. The next 30 minutes, the research assistant spoke to the baby in, say, Spanish. Babies will change the way they babble depending on who they're interacting with. So if the person interacting with them was interacting in English, it's the same baby in the same one hour slot. in the first 30 minutes, because the person talking to them was in English, their utterances

were shorter. And in the second session, when it was a Spanish speaking person, their utterances were longer, had more syllables in it. That's how plastic they are and how attuned to the context. Because, yeah, it's communication. They are communicating with this person. They will do what this person does if they can. It's very polite, baby.

Very polite baby. So see, if there is a monolingual baby and you do the exact same thing to them, they won't change the way they babble with the Spanish-speaking person. Oh. They won't. They won't do it. But if you bring a monolingual baby, say a nine and a half-month-old monolingual baby into the lab, and expose them to Spanish for, say, 30 minutes, two to four times a week for about four weeks.

And in these sessions, you're just reading to them, playing with them in Spanish. What happened? Oh. Then when you bring them back at 12 months and you do the exact same experiment, they will change their babbling. So they only need about five hours of exposure to this other language before they're able to change their babbling. It's impressive.

It really is. So I'm wondering, can any of this research be something that adults might try to replicate to become better language-looking? learners because I have the Duolingo app and it and I have a love-hate relationship and I will take any tips that I can get. You know, there are a couple of things that work for babies that work for adults too. One is learning is social.

You know, I told you five hours of exposure to a person playing and reading is going to help this baby tune into this other language. Humans also will best learn language, say in immersion context, right? You go somewhere, you live there. hey, this is now meaningful. Social interaction, it's contingent. It gives you feedback. It gives you rewards, reinforcement, all of that.

So that's a thing that babies learn the same way and adults learn the same way. So you need to just put yourself out there. Completely. And early exposure. If you get very early exposure, even if you never learned that language fully, you come back to it as an adult, you're going to have a head start. Completely. It's amazing.

All right. I need to early expose my child to all of the languages so that he is a language genius. Yes. Little baby genius. Yes, so cute. So this is why I love my job, you know. Yeah. No matter what the babies do, they're cute. Yeah. And then something happens, and they all come into adults. Yeah.

All right, well, Dr. Megas Sundara, thank you so much for being here. Thank you so much for inviting me. My pleasure. This episode was produced by Carly, Rubin and Britt Hanson. It was edited by managing producer Rebecca Ramirez. Britt Hansen, Will Chase, and Katie Doggart check the facts. Josh Newell was the audio engineer. Beth Donovan is the senior director of programming. Anya Grunman is the senior vice president of programming. I'm Sidney Lupkin. Thanks for listening to Shortwave from NPR.