0:00:05 > 0:00:08# If you've got a question and you don't know where to go
0:00:08 > 0:00:11# Ask Nina for some help Cos she's got a science show
0:00:11 > 0:00:15# She makes sense of her senses While helping all her fans
0:00:15 > 0:00:17# By doing her experiments with potions and with bangs
0:00:17 > 0:00:19- # Touch your tongue- Tongue!
0:00:19 > 0:00:20- # Fingers- Fingers!
0:00:20 > 0:00:23- # Eyes- Eyes! - Ears- Ears!- Nose- Nose!
0:00:23 > 0:00:26# Nina and the Neurons find out what you need to know
0:00:26 > 0:00:30# Nina and the Neurons find out what you need to know
0:00:30 > 0:00:32# Luke, he helps us with our eyes and Felix with our touch
0:00:32 > 0:00:35# Ollie sniffs out smells And Belle, she hears so much
0:00:35 > 0:00:38# Bud is Ollie's brother He helps us with our taste
0:00:38 > 0:00:41# They're Nina's little neurons And they're coming to your place!
0:00:41 > 0:00:43- # Touch your tongue- Tongue!
0:00:43 > 0:00:44- # Fingers- Fingers!
0:00:44 > 0:00:47- # Eyes- Eyes! - Ears- Ears!- Nose- Nose!
0:00:47 > 0:00:51# Nina and the Neurons find out what you need to know
0:00:51 > 0:00:54# Nina and the Neurons find out what you need to know
0:00:54 > 0:00:56# Oh yeah! #
0:00:56 > 0:00:58Oh, hello!
0:00:58 > 0:01:00I'm doing some experiments about waves.
0:01:00 > 0:01:04When I touch the water, it makes waves scatter out
0:01:04 > 0:01:06- in all directions. - BEEPING
0:01:06 > 0:01:11Oh! I hear a beep, I see a flash! I wonder what they're going to ask.
0:01:18 > 0:01:21- ALL: Hi, Nina! - Hi, guys!
0:01:21 > 0:01:24We've got a question - how do speakers work?
0:01:24 > 0:01:28That's a great question! How do speakers work?
0:01:28 > 0:01:32Speakers are a great invention because they allow us to hear music,
0:01:32 > 0:01:34voices and... Oh, hang on!
0:01:34 > 0:01:37I can hear YOUR voices through my speakers here!
0:01:37 > 0:01:41- Come to my workshop and we'll check it out.- Bye, Nina!
0:01:41 > 0:01:43Bye!
0:01:43 > 0:01:47I'm going to need help to answer this one. I know just who to ask.
0:01:47 > 0:01:50OK, neurons, time to get to work!
0:02:06 > 0:02:09ALL: Neurons at the ready, Nina!
0:02:09 > 0:02:13Today's question is how do speakers work?
0:02:13 > 0:02:17Which neuron do you think would be most useful in finding the answer?
0:02:17 > 0:02:20- Me!- Me!- Me!- Me!- Me!
0:02:20 > 0:02:23Will it be...fabulous Felix?
0:02:23 > 0:02:27I can help so very much if you need the sense of touch.
0:02:27 > 0:02:29Will it be...beautiful Belle?
0:02:29 > 0:02:31I send messages from brain to ear
0:02:31 > 0:02:36- If there's a sound, I'll help you hear.- Will it be...lovely Luke?
0:02:36 > 0:02:38For looking and seeing day and night
0:02:38 > 0:02:41I'll help you with your sense of sight.
0:02:41 > 0:02:44- Will it be awesome Ollie? - If it's pongy or whiffy
0:02:44 > 0:02:47but you can't tell, my messages help your sense of smell.
0:02:47 > 0:02:51- Or will it be baby Bud? - Sour, salty, bitter or sweet
0:02:51 > 0:02:54I'm your taste buddy Whenever you eat.
0:02:58 > 0:03:00It's Belle!
0:03:00 > 0:03:03- Yes! ALL:- Go, Belle! Go, Belle!
0:03:03 > 0:03:07Go, Belle! Go, Belle! Go, Belle!
0:03:07 > 0:03:10Brilliant! I'm all ears, Nina!
0:03:10 > 0:03:14Today's question is how do speakers work?
0:03:14 > 0:03:16Because speakers send out sounds,
0:03:16 > 0:03:19we need hearing neuron Belle to help us.
0:03:19 > 0:03:22But I may need help from all of you!
0:03:22 > 0:03:26I need to get the workshop ready before the inventors arrive.
0:03:28 > 0:03:32Emma, Mairi and Isabella want to find out about speakers -
0:03:32 > 0:03:35loud speakers, cool speakers, dancing-round-your-room speakers.
0:03:35 > 0:03:39Today, for one day only, Emma, Mairi and Isabella become
0:03:39 > 0:03:41the inventors!
0:03:43 > 0:03:46- Hi, guys! - ALL: Hi, Nina!
0:03:46 > 0:03:49Lovely to see you! Thanks for coming.
0:03:49 > 0:03:52Your question is, how do speakers work?
0:03:52 > 0:03:56- Why do you want to know?- Our computers at home need speakers.
0:03:56 > 0:03:59And we want to know how music comes out of them.
0:03:59 > 0:04:03Well, sound travels in invisible waves.
0:04:03 > 0:04:07For example, as I am speaking to you, my voice is travelling
0:04:07 > 0:04:10in invisible waves towards your ears.
0:04:10 > 0:04:14- Even though we can't see them, we can hear them, can't we?- Yes.
0:04:14 > 0:04:18Over here, I've a plate with some beads on,
0:04:18 > 0:04:21and I've sat it on top of one of my own speakers.
0:04:21 > 0:04:24Now, I'm going to play some music. Let's see what happens.
0:04:25 > 0:04:27MUSIC BEGINS
0:04:27 > 0:04:29NINA LAUGHS
0:04:32 > 0:04:36- The beads are jumping up and down! - That's right!
0:04:36 > 0:04:39It's vibrations that's making the beads jump!
0:04:39 > 0:04:42Vibrations are actually waves of air,
0:04:42 > 0:04:46and when the waves of air reach our ears,
0:04:46 > 0:04:51we hear them as sound. So speakers send out sound waves.
0:04:51 > 0:04:54- How do they do that? - Let me turn this off.
0:04:55 > 0:04:59I think we need to get inside and have a closer look.
0:04:59 > 0:05:02Taking things apart is my job. It can be dangerous
0:05:02 > 0:05:05- so don't do this yourself. - That's right!
0:05:05 > 0:05:07Nina's been trained to do this.
0:05:07 > 0:05:10If YOU open things that use electricity,
0:05:10 > 0:05:12you could hurt yourself.
0:05:12 > 0:05:16I'm going to use the the Nina-cam to have a closer look.
0:05:16 > 0:05:19Here we have some wires...
0:05:20 > 0:05:25..and a cone. We know that sound waves are created by vibrations,
0:05:25 > 0:05:30and in a speaker, vibrations are caused by electricity.
0:05:32 > 0:05:35So the electricity comes through these wires
0:05:35 > 0:05:37and goes to a little disc that's hidden
0:05:37 > 0:05:41beneath this cone. Now, that brown disc there
0:05:41 > 0:05:44is called the diaphragm,
0:05:44 > 0:05:46and it vibrates. And when it vibrates
0:05:46 > 0:05:51it creates sound waves which travel through the air to our...
0:05:51 > 0:05:52ear!
0:05:52 > 0:05:54Ho-ho-ho!
0:05:54 > 0:05:58# Ta-da! # I'm a sound neuron - this is my job!
0:05:58 > 0:06:00That's right! You're doing a great job.
0:06:00 > 0:06:05We know that on a speaker, the disc vibrates and sends out sound waves.
0:06:05 > 0:06:09But what about that cone? Why do speakers have cones?
0:06:09 > 0:06:12We might get a clue if we look at an invention
0:06:12 > 0:06:14that helps lots of people hear things.
0:06:14 > 0:06:18- Would you like to see another invention in action? - ALL: Yeah!
0:06:18 > 0:06:20Cool! Let's go!
0:06:25 > 0:06:30Off they go. I really enjoy seeing the big inventions.
0:06:30 > 0:06:35What helps lots of people hear things at the same time?
0:06:35 > 0:06:38Nina said it had something to do with a cone.
0:06:38 > 0:06:42Looks like we'll find out soon enough. We're here!
0:06:43 > 0:06:47Oh, I love the seaside! It's one of my favourite places
0:06:47 > 0:06:51to do experiments. Today I've got a great experiment for us.
0:06:51 > 0:06:53Emma, can you take the red flag, please?
0:06:53 > 0:06:55Isabella, the green flag,
0:06:55 > 0:07:00- and Mairi, you have the yellow.- Are we going to wave them?- Yes, you are!
0:07:00 > 0:07:04- Do you see the end of the beach, over there?- Yes.
0:07:04 > 0:07:06Can you guys go and stand over there
0:07:06 > 0:07:11and I'm going to shout a colour, and you wave that colour of flag.
0:07:11 > 0:07:15But how are we meant to hear you if we're far away?
0:07:15 > 0:07:18Ah, well that's where this might come in handy.
0:07:18 > 0:07:20This is a megaphone,
0:07:20 > 0:07:25and it's a really big cone, and similar to a cone inside a speaker.
0:07:25 > 0:07:27OK, off you go!
0:07:31 > 0:07:34There they are. They're in position.
0:07:35 > 0:07:37Red!
0:07:40 > 0:07:42Red!
0:07:45 > 0:07:47RED!
0:07:50 > 0:07:54It works! It works! They heard you, Nina!
0:07:54 > 0:07:57They have, Belle! They heard me when I used the megaphone
0:07:57 > 0:08:00but not when I used my own voice.
0:08:00 > 0:08:01GREEN!
0:08:06 > 0:08:07Yellow!
0:08:11 > 0:08:13YELLOW!
0:08:15 > 0:08:19Wow, this megaphone works really well!
0:08:19 > 0:08:22I think it's time to get them back now.
0:08:22 > 0:08:24OK, guys! Come back!
0:08:26 > 0:08:30Hey, guys, how well did you hear me?
0:08:30 > 0:08:34At the beginning we could hear something, but we didn't know what!
0:08:34 > 0:08:37When you used the megaphone, we could hear you well!
0:08:37 > 0:08:39So, cones DO make sound louder!
0:08:39 > 0:08:42And it's because of their shape.
0:08:42 > 0:08:46The shape of it makes my voice go in just one direction,
0:08:46 > 0:08:50rather than all over the place, so it makes it sound louder.
0:08:50 > 0:08:53Now that we know lots about cones and speakers,
0:08:53 > 0:08:58we should go back to the workshop and GET INVENTING! Let's go!
0:09:00 > 0:09:05Speakers are so useful. Life would be much too quiet without them.
0:09:05 > 0:09:07But who invented the speaker?
0:09:07 > 0:09:11Listen to me, everyone! I can tell you!
0:09:11 > 0:09:15Over 100 years ago,
0:09:15 > 0:09:18there was a man called Alexander Graham Bell.
0:09:18 > 0:09:21His mother and his wife were both deaf,
0:09:21 > 0:09:25and that's why he became interested in things to do with sound.
0:09:25 > 0:09:29He knew all about vibrations and sound waves.
0:09:29 > 0:09:34Alexander Graham Bell was actually inventing the telephone, when...
0:09:34 > 0:09:38he invented the first ever speaker!
0:09:38 > 0:09:40What a clever man!
0:09:43 > 0:09:46So, you asked, how does a speaker work?
0:09:46 > 0:09:51So far we've found out that sound is carried in waves and vibrations.
0:09:51 > 0:09:55And then we looked inside a speaker and saw wires went to a little disc
0:09:55 > 0:09:59and made it vibrate. And that vibrating disc sent out sound waves
0:09:59 > 0:10:03which we can hear. There is also a cone in a speaker,
0:10:03 > 0:10:06so I wonder what the cone does.
0:10:06 > 0:10:11I think we should get inventing to find out! For today's invention,
0:10:11 > 0:10:15we're going to make a mini speaker. The first thing we're going to do
0:10:15 > 0:10:20is draw around the bottom of the cup. Once you've done that,
0:10:20 > 0:10:23we're going to cut these out. We're going to cut two discs.
0:10:23 > 0:10:29- A disc is just a circle. - Yes, here it is - one round disc.
0:10:29 > 0:10:33The next thing I'd like you guys to do is glue the first disc
0:10:33 > 0:10:35to the bottom of the cup.
0:10:35 > 0:10:39Now, we're going to attach...the cup
0:10:39 > 0:10:44to...our stick, and push it through
0:10:44 > 0:10:48so you can feel it's gone to the other side of the cup.
0:10:48 > 0:10:52Next, we're going to attach the second disc to another stick.
0:10:52 > 0:10:55So, on the flat side... I just need sticky tape.
0:10:55 > 0:10:58And in the middle...
0:10:58 > 0:11:03like that. OK. Now we're going to take THIS disc, with no cup,
0:11:03 > 0:11:06and stick it in this one.
0:11:06 > 0:11:10And now stick that one in here. Take a pencil
0:11:10 > 0:11:16and, with the pointy end, we're going to rub the back of this disc
0:11:16 > 0:11:21- and listen carefully. - SCRAPING
0:11:21 > 0:11:26- It makes a clickety sound, and it's quite quiet.- It IS quite quiet.
0:11:26 > 0:11:32Let's try doing the same on the disc attached to the cup.
0:11:34 > 0:11:38- That one's much louder.- It IS louder
0:11:38 > 0:11:43and that's because the cup, like a speaker cone, is vibrating too.
0:11:43 > 0:11:48It makes the sound waves stronger. A speaker cone works the same way.
0:11:48 > 0:11:53- And the stronger the sound waves, the easier it is to hear.- Exactly, Belle!
0:11:53 > 0:11:58And there you have it. You've made your very own mini speaker!
0:12:01 > 0:12:06Your question was, how do speakers work? I think we've answered it.
0:12:06 > 0:12:10We found out that sound is caused by vibrations
0:12:10 > 0:12:14that travel through the air in sound waves. We looked inside a speaker
0:12:14 > 0:12:18and saw a small disc that vibrates. When that disc vibrates,
0:12:18 > 0:12:21it creates sound! We also saw a cone inside the speaker.
0:12:21 > 0:12:25Without the cone, the disc just makes a small sound.
0:12:25 > 0:12:30The cone makes it sound much bigger because the cone vibrates too,
0:12:30 > 0:12:34making the sound waves stronger. That's how a speaker works!
0:12:34 > 0:12:38- Thanks for coming down to see me. - Thanks, Nina! Bye!
0:12:38 > 0:12:40Take care!
0:12:44 > 0:12:49If you want to make today's invention, go to the Nina section
0:12:49 > 0:12:52on the CBeebies website for all the instructions.
0:12:52 > 0:12:56Or you may have other ideas you want to invent!
0:12:57 > 0:13:03- Bikes!- Planes!- Speakers- And cars!
0:13:03 > 0:13:05# We all love inventing
0:13:05 > 0:13:09# Whoa, love inventing!
0:13:09 > 0:13:11# We all love inventing
0:13:11 > 0:13:14# Why don't you try it too?
0:13:14 > 0:13:17# Inventions make life easier
0:13:17 > 0:13:21- # And help us get things done - Go inventing!
0:13:21 > 0:13:26# I always like to take a look at how they work and run
0:13:26 > 0:13:27# Go inventing!
0:13:27 > 0:13:33- # We all love inventing - Whoa, go inventing!
0:13:33 > 0:13:39# We all love inventing Why don't you try it too? #
0:13:39 > 0:13:41It's been a marvellous day!
0:13:41 > 0:13:45I particularly liked feeling the vibrations.
0:13:45 > 0:13:49Ah, it's been such a great day, man!
0:13:49 > 0:13:52It was so fascinating to see inside a speaker!
0:13:52 > 0:13:55The wires, the disc, the cone!
0:13:55 > 0:13:58I really enjoyed myself today.
0:13:58 > 0:14:02It was really funny when Nina used the megaphone to call the inventors.
0:14:02 > 0:14:08I've had a fabby day! I liked the clickety noise maker best!
0:14:08 > 0:14:13The cone shape of the cup made the noise even LOUDER!
0:14:13 > 0:14:17Our day's been bursting with inventions.
0:14:17 > 0:14:21- I hope you've enjoyed it! See you again soon! Bye!- Bye!