Neil: And hello! I'm Neil.

Rob: Hi there Neil. Have you ever had a close encounter with a monkey or an ape?

Neil: Well I'm sitting right next to you, Rob?

Rob: Very funny. Neil is referring to the fact that

all humans are descended from apes,

and apes and monkeys belong to a group of animals called primates.

The difference is that monkeys have tails, and apes don't.

Neil: Well, I didn't know that. On a serious note...

I had a close shave with some monkeys once in Bali.

Rob: A close shave is where you only just manage to avoid a dangerous situation.

So Neil, what happened?

Neil: I was walking up a mountain on my own

and suddenly a bunch of monkeys jumped out of nowhere, blocking my path.

Rob: Oh goodness! OK. So what did you do?

Neil: After standing there for ages while the monkeys screeched at me,

I turned round and walked back the way I came.

Rob: OK. If you screech at someone it means to make a loud, high and unpleasant sound.

So the monkeys won that face-off, then!

Neil: Absolutely! Yes, they did! And a face-off,

by the way, means an argument or fight.

Rob: Well, today's show is about gibbons and the different sounds they make.

Gibbons are small apes that live in Southeast Asia.

And while Neil's monkeys screech unpleasantly,

gibbons sound like they are singing.

Neil: Musical apes... that's nice! So how about today's quiz question, Rob?

Rob: OK, good idea. How far can a gibbon's voice travel through the forest? Is it... a) 500m

b) 1km or c) 5km?

Neil: Hmm. Well, I have to guess and I'm going to say b) 1km.

Rob: You've never heard one.

Neil: Never heard one...

Rob: OK. We'll find out later on in the programme whether you're right or wrong.

Now let's listen to what a gibbon really sounds like.

Interviewer: Let's just hear this. That's an absolutely wonderful, evocative sound, isn't it? Beautiful sound.

And what are they doing there then? That is ... I said talking to each other.

Dr Clarke: Well this is their ... They're singing together.

So a male and a female, when they hold a territory together,

will sing every morning what they call a duet. All the groups...

Interviewer: What we call a duet.

Dr Clarke: Yes, absolutely. And they'll all sing together at the same time,

and the whole forest will be alive with this cacophony of song.

Rob: So the gibbons make an evocative sound.

If something is evocative it brings strong feelings or memories to mind.

Neil: And something that is evocative is usually pleasant, Rob.

Rob: It is. And what's also interesting is that the apes are singing in pairs, one male and one female.

They are singing duets together.

So a duet is a song sung by two people or in this case, sung by two gibbons!

Neil: And a lot of gibbons are singing duets at the same time

which Dr Clarke describes as a cacophony.

Cacophony means a mix of loud noises, which often sound out of tune.

Rob: And that could easily describe us singing together!

Neil: Let's not do that.

Rob: But what's the reason for the gibbon duets, Neil?

Neil: Well, the songs advertise the relationship between the male and the female.

And they also help to make clear which territory

or bit of land belongs to a pair or group of gibbons.

Rob: Gibbons also use different sounds to alert

or warn other gibbons about danger from predators these are animals that eat other animals.

The gibbons use a quiet 'hoo hoo' call to communicate that a leopard is nearby,

and an even quieter 'hoo hoo' call for an eagle.

Neil: You're very good at that Rob.

Rob: Thank you.

Neil: Now let's hear more from Dr Clarke about this.

How does she describe language?

Dr Esther Clarke Yes, so the idea is that if we find things like context-specific calling in non-human primates,

it suggests that way back in time

the ancestor that we shared with them also had context-specific calling so basically

it just gives us some clues [as] to the evolutionary roots of complex communication like language.

Rob: Dr Clarke says that if we go far enough back in time humans

and other primates such as monkeys and apes have the same ancestor.

Neil: Right. And ancestor means an animal or human

from the past that a modern animal or human has descended from.

So if this common ancestor used context-specific calls like modern gibbons,

then it could have passed on this ability to humans a long time ago.

Rob: Context-specific calling means different calls for different situations,

for example one call for 'leopard' and another for 'eagle'.

Neil: And evolutionary means a gradual process of change or development.

Rob: OK, let's have the answer to the quiz question.

Earlier I asked: How far can a gibbon's voice travel through the forest? Is it: a) 500m

b) 1km or c) 5km?

Neil: And I said b) 1km.

Rob: And you were right! A good guess!

Perhaps you do know a lot about gibbons. So well done!

Now, can we hear today's words again maybe in a gibbon's voice Neil?

Neil: I'm not sure about that. I'll do it in a human voice.

primates

a close shave

screech

face-off

gibbons

evocative

duet

cacophony

territory

alert

predators

ancestor

evolutionary

Rob: Thank you. Well, that's the end of today's 6 Minute English.

You can hear more 6 Minute English programmes on our website at bbclearningenglish.com.

Please join us again soon.

Both: Bye.