Why animals can't talk (but almost can)

0:00 What would it sound like if a monkey proposed?

0:03 "Will you marry me?" How would an elephant call your name?

0:07 Can parrots really speak?

0:09 And does the giraffe have anything to say at all?

0:13 You're about to find out as we

0:15 explore the spoken language of the animal kingdom.

0:18 It's time to talk with the animals in another RobWords.

0:24 These are the Barbary macaques at Berlin's Tierpark Zoo.

0:29 Did you know that no nonhuman primate has ever been taught to speak?

0:34 You've perhaps seen videos of Nim Chimpsky,

0:37 the chimpanzee who was raised to use American Sign Language,

0:42 and other members of that species have

0:45 found remarkable ways to communicate with us.

0:48 [Video narrator] “Tim, please tickle Lana.” “Yes”, replies Tim.

0:55 “Lana, come here.” [Rob] That's absolutely incredible, isn't it?

1:00 But it's not speech.

1:02 It's not vocal language.

1:04 And one of the reasons that a chimpanzee has never

1:06 said a word is that their anatomy makes it basically impossible.

1:11 They lack the long vocal tracts that we have,

1:14 the versatile tongues for shaping the sounds, and also the mouths that we have,

1:19 which are kind of small but enable us

1:22 to control the noises we make with incredible precision,

1:27 when you think about it.

1:29 But they also don't appear to have the neural

1:32 wiring that allows us to make these complex, voluntary sounds on demand.

1:38 However, research conducted within the last decade suggests some primates,

1:44 if they could get over that sizable neurological hurdle,

1:48 might be physically speech ready.

1:51 In 2016, researchers set out to challenge the idea that monkeys,

1:55 specifically macaques like we have here at the Tierpark,

1:59 couldn't speak if they wanted to.

2:01 So instead of– as had been previously done– poking

2:04 around the vocal tracts of dead or sedated monkeys,

2:09 they took X-ray footage of macaques doing

2:13 various things like eating and making sounds.

2:17 And from that, they tried to work out

2:20 what sounds the macaque might be capable of making,

2:23 given the amount of different movements that their vocal

2:27 tract and their mouth could actually perform.

2:30 And what they concluded was that it was a lot.

2:34 They said “if a macaque monkey had a brain

2:37 capable of vocal learning and combinatoric operations over speech sounds,

2:42 its vocal tract would be able to produce clearly intelligible speech.” So

2:49 the researchers reckoned that the macaques would be able to make, for a start,

2:53 five different vowel sounds,

2:55 which maybe doesn't sound like very much– English has a lot more than five–

3:00 but actually five vowel sounds is around

3:02 about the average for languages around the world,

3:05 so that wouldn't get in the way of them being understood by humans.

3:08 They also reckon that they'd be able to produce

3:10 quite a lot of consonant sounds as well.

3:12 What are called stop consonants like “kuh” and “guh”, like that.

3:16 And then other sounds as well, like “wuh” and “muh”.

3:20 They'd have been capable of producing those.

3:23 So you might be wondering: “If a macaque could talk,

3:26 what would it sound like?” Well,

3:29 the researchers anticipated that question and attempted to recreate that sound.

3:35 I'm going to warn you here: this is creepy.

3:38 This is what a macaque would sound like if it got down on one knee and proposed.

3:44 “Will you marry me?” And again.

3:46 “Will you marry me?” Yeah, like I say, a bit creepy.

3:51 And did you also detect a slight sort of accent in there?

3:55 “Will you marry me?” Now,

3:56 that's because of what I was talking about, about the vowel sounds.

3:59 So English has anywhere between fifteen and twenty something vowel sounds,

4:04 depending on who you ask.

4:07 And so if a macaque could only actually produce five vowel sounds,

4:11 it would have to re-appropriate some of those sounds and apply

4:15 them to some of our vowel sounds that it doesn't have.

4:17 And that's how you end up with a macaque that sounds a little bit exotic.

4:23 “Will you marry me?” It's comprehensible, isn't it?

4:26 But it is also extremely hypothetical.

4:29 These macaques might have speech ready bodies,

4:32 but they do not have speech ready brains.

4:36 So let's talk about some of the remarkable things

4:38 that some monkeys already do because they are worth talking about.

4:42 These are vervet monkeys and unusually for monkeys,

4:45 they like to spend their time on the ground,

4:48 but that makes them susceptible to threats

4:50 that other monkeys are less likely to experience.

4:53 However, they've come up with a very

4:55 clever way to deal with that additional threat.

4:58 This lookout vervet will make a different sound depending on what the danger is.

5:05 For example, this sound means, “Snake!

5:10 Watch out!

5:10 Stand up and look down.” This sound means, “Watch out!

5:15 Eagle!

5:15 Get deep into the trees where the birds

5:19 can't fly at you.” And this sound says, “Careful!

5:23 Leopard!

5:24 Get into the trees and get to the end of the branches so that big cat

5:30 can't grab you.” Each of these sounds carries

5:32 a different meaning and triggers a different behaviour,

5:35 making them almost like words.

5:40 However, “almost” is the key word there because they

5:43 are not words for reasons that I will explain.

5:47 Now when you think of whalesong, you perhaps think of this.

5:51 [Whale] WhoooOOooooOOoo.

5:52 However, they don't all communicate like that.

5:54 Sperm whales, for example, communicate exclusively with clicks.

5:59 And an amazing bit of new research suggests that what they do

6:02 with those clicks might be remarkably similar to something that humans do.

6:08 Thanks to this video's sponsor, Ground News,

6:10 I can see that researchers at UC Berkeley studied around nine thousand

6:14 recordings using AI models described as “ChatGPT

6:18 for whales” to identify vocal patterns,

6:21 and what they concluded was that sperm whale clicks appear to work

6:25 like the vibrations that create human vowel sounds, just much slower.

6:32 It challenges the previous idea that these clicks were some sort of Morse code.

6:37 Pretty cool.

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7:32 So we've heard how macaques might be able to make sounds like humans,

7:37 and how the clicks of sperm whales are like a very slow vowel movement.

7:42 But there are animals that can produce

7:45 sounds that sound almost exactly like human speech.

7:48 In fact, they can be indistinguishable.

7:51 I'm talking about birds.

7:53 Now, I was hoping to show you a few here at the Tierpark,

7:56 but because of an outbreak of bird flu in Europe,

7:59 they've kept them all safely inside.

8:01 However, let's talk about these guys.

8:05 Let's talk about parrots, because parrots are the closest thing we

8:11 have to a non-human animal that can speak.

8:15 Would you like to hear an African grey

8:18 parrot reciting parts of the Quran in Arabic?

8:21 Yes.

8:21 Here you go.

8:23 [Mudalal the parrot speaking Arabic] An even more impressive

8:31 African grey called Alex is said to have been

8:34 the first non-human to ask an existential question when

8:39 one day he looked in the mirror and said, “What color?” The answer was grey.

8:46 So parrots can produce speech-like sounds,

8:48 but they do it in a different way to we do it.

8:53 So we have a larynx at the top of our trachea, right?

8:58 So we have air that goes up and then

9:00 through the voicebox and then out through our mouths,

9:03 and that's how we make sounds.

9:05 Birds have something else.

9:08 They have something called a syrinx instead of a larynx,

9:10 which sits at the bottom of the trachea and manipulates

9:14 the sound down there before sending it up through the windpipe.

9:18 And usually that comes out as a squawk or whatever.

9:22 But with parrots, they, like us,

9:24 have very versatile tongues that can further manipulate the sound,

9:29 and they have beaks that they can open or close just about as much as they want,

9:34 again giving them more control over the sound.

9:38 This means they can essentially talk …but they're not talking.

9:44 Now, Alex was sadly cut down in his prime in 2007 at the age of just 31.

9:50 They can live twice as long as that.

9:52 He had more to learn.

9:53 But his legacy was leaving linguists to reassess whether

9:58 humans really are the only animals that can truly speak.

10:03 So let's talk about what human language does that other animals don't achieve,

10:08 because linguists have put a lot of thought into this.

10:12 Back in 1960, a fellow called Charles

10:15 Hockett proposed thirteen design features for language.

10:19 It was a list of thirteen things that make languages languages.

10:24 Now, nowadays they are best described as features of spoken

10:28 language because in the 65 years since Hockett published his list,

10:32 sign languages have been rightly recognized as fully fledged languages,

10:36 despite not having all of these features.

10:40 Now, Hockett didn't intend his list to be

10:42 used to compare humans and other animals, but by looking at it,

10:45 we can see that there is, at the very least,

10:48 a trio of these thirteen features that no

10:52 non-human species has managed to nail down.

10:55 Firstly, what he called “traditional transmission”.

10:58 Languages are transmitted non-genetically by social learning and teaching,

11:03 whereas animals, their noises tend to be wired in their instinctive.

11:08 Though we have taught other animals to say things,

11:11 they haven't taught these things to each other.

11:14 The second feature is “displacement”.

11:15 This is a really key one.

11:16 It's the ability to talk about things that are not present in the here and now.

11:20 Humans can say, “I saw a dog yesterday.” Other animals cannot.

11:26 And a third is “productivity”.

11:29 The fact that human language is inexhaustive.

11:32 I can right now say a sentence that has never been uttered before:

11:37 “My ginormous aardvark just bikini-waxed a bison.” And what's more,

11:43 you can understand it.

11:45 The possibilities are endless.

11:47 Whereas with animal sounds, they're limited to a specific repertoire.

11:52 At the same time, that repertoire can be pretty impressive.

11:56 Some animals are capable of noises that we couldn't even dream of.

12:00 Elephants, for example, can produce sounds so deep that we can't even hear them,

12:06 let alone replicate them.

12:08 I'm going to come out of there because it's a bit silly.

12:10 But when you think of elephants, you probably think of trumpeting trunks.

12:16 But that's not actually the sound that keeps elephant societies together.

12:20 That is the elephant rumble.

12:24 Elephants produce deep rumbling sounds that can

12:27 travel huge distances and say things like,

12:30 “Hey, I'm over here!” to other elephants in the vicinity,

12:34 or “Guys, it's time to go.” when the herd

12:37 has finished its brief stop at the watering hole.

12:40 But what's amazing about these rumbles is that often they are infrasonic.

12:47 That means they occur at frequencies that are

12:50 below the levels that humans can hear.

12:53 We know when they're being made a lot of the time

12:55 because they produce harmonics that we actually can hear.

12:58 But the sounds themselves, most of it is inaudible to human beings.

13:03 But recent research suggests that one of the things

13:05 the elephants are doing with these rumbles is remarkably human-like.

13:10 It suggests they're calling each other by name.

13:15 The researchers at Colorado State University said that “African

13:20 elephants address one another with individually specific name-like calls”.

13:26 I'll allow them to explain.

13:28 “We played back calls that we had high confidence,

13:31 that had names and and calls that we

13:33 had high confidence that they weren't, uh, labeled.

13:37 And we played those back to individuals.” [Low rumbling sound] [Low rumbling

13:45 response] “And we found responses to the calls that we assumed had

13:50 a good chance of vocal labeling.” Not only that, but when the Elephant

13:54 was played a clip that featured the name of a different elephant,

13:58 they just ignored it because it wasn't addressed to them.

14:02 Now, with all this name stuff, you might be thinking,

14:05 “Yeah, well, other species do that too.” Well, yeah, but no.

14:09 Not like this they don't.

14:11 Dolphins and parrots call each other by “name”

14:14 by actually imitating the signature call of the addressee.

14:19 It's like calling Homer Simpson “D’oh!” instead of calling him Homer.

14:25 But what elephants are doing is creating

14:29 these abstract sounds to refer to specific individuals.

14:34 It's amazing because it's what we do.

14:38 That's exciting, isn't it?

14:39 But do you know what else is exciting?

14:42 That I am doing my first ever live show.

14:46 RobWords Live is coming to London's Bloomsbury Theatre on 11th April, 2026.

14:53 I am extremely excited about it.

14:55 It's going to be an evening of etymology and general word nerdery.

14:59 If you want to join me for it and let me see that lovely face of yours,

15:03 I'll leave a link below to where you can buy tickets.

15:06 Come join me for RobWords Live.

15:09 Now if you spend a lot of time in the forest,

15:11 as I clearly do, you'll be well aware of the call of the red deer.

15:17 However, did you know that red deer stags actually have two types of calls?

15:22 They have what zoologists call their “common roar”,

15:24 the one unsurprisingly, they use most often,

15:27 and they also have their “harsh roar”,

15:29 which is the one that they use a bit more sparingly.

15:32 It's, as the name suggests, harsher on the ears and is most likely used

15:37 for grabbing the attention of ladies during the rut.

15:40 I don't know why I said that in a sexy way.

15:42 The common roar is actually really fascinating though,

15:45 because it is distinct to the individual and intrinsic to the sound

15:50 is objective information about the stag who is emitting it,

15:55 including an honest appraisal of the stag's size.

16:00 That means that despite the image we like

16:02 to think of, of stags going antler to antler,

16:05 they actually don't come to blows as often as they might,

16:09 because from the roars alone,

16:11 two stags can establish who would win if they did fight.

16:16 And usually that's enough to encourage the lesser stag to just,

16:20 you know, leave it out.

16:22 So a roaring stag might seem like it's spoiling for a fight,

16:25 but actually it might just be trying to avoid one.

16:29 So the stag roars, the elephant trumpets or grumbles,

16:33 the cat meows and the dog barks.

16:36 But what does the giraffe do?

16:40 Well, let's talk about an animal from whom we barely hear a peep,

16:43 because actually, giraffes are capable of making sounds.

16:47 Well, firstly, they can snort, they can produce bursts,

16:52 and as this video shot right here at Berlin's Tierpark shows,

16:56 they can also grunt.

16:57 Just listen carefully for it.

17:00 [Brief snort] [Replay of snort] But it is true that you

17:06 will very rarely hear an adult giraffe make a sound.

17:09 And that's weird, because giraffes are pretty sociable animals,

17:14 and animals with similar social structures like elephants,

17:17 can barely keep a lid on it.

17:19 So what's the deal with giraffes?

17:22 Well, it was thought that one of the reasons they don't make

17:24 a lot of sounds is that they can't because of their long necks.

17:27 It somehow makes getting the sound up and out there a bit harder.

17:31 And it's also thought that maybe they're doing what I was saying elephants do,

17:35 which is make ultrasonic sounds that we can't hear.

17:39 There are certain movements that giraffes make that seem a little bit bizarre,

17:43 but some zoologists think might be associated with production

17:46 of a noise that our ears don't pick up.

17:49 However, research carried out here in Berlin

17:52 and at two other zoos in Copenhagen and Vienna,

17:56 found that giraffes were making another

17:59 noise that we previously didn't know about.

18:02 They were humming to one another.

18:05 The researchers set up microphones in the stalls

18:08 where they put the giraffes here at night,

18:11 and they recorded hundreds of hours of audio.

18:14 And in among those hundreds of hours of basically silence, they heard this.

18:22 [Deep humming sound] Okay, so it sounds like someone having trouble

18:34 on the toilet in the middle of the night.

18:38 [Replay of deep hum] But that sound is remarkable.

18:40 And it only occurs sixty five times in the nine

18:44 hundred hours of audio that the researchers recorded.

18:48 But they describe that hum as probably a contact call,

18:53 a sound made by the giraffes to reassure each

18:56 other from their separate stores that they're still there.

19:00 So the lion roars, the elephant trumpets, and the giraffe does what?

19:05 Well, it hums.

19:08 And that brings to an end our conversation with the animal kingdom.

19:12 But one key question remains, doesn't it?

19:15 If animals can't speak, why can we?

19:18 Well, that's a question that I will answer on this channel in the coming months,

19:22 so do keep an eye out for that.

19:25 Thanks to Tierpark Berlin,

19:26 Colorado State University and Professor Julian Pine from Liverpool

19:30 University for all their help with this video.

19:33 Thanks to you for watching it as well.

19:35 I recommend you maybe watch this one next.

19:39 Check out Ground News and of course RobWords Live tickets in the links below.

19:44 And until next time, take care.