Lesson video

Hello, everybody.

Welcome back to your science lessons with me, Miss Roberts.

It's so great to see you all back here today.

Today we are going to be looking at the science of acoustics.

Now, I wonder what can you see behind me? I'm at a football stadium today and a stadium is a really, really big place.

You can see that there are lots of people in the crowd.

You can see that there's grass on the lawn.

And then, can you have a look at the roof? That looks very interesting, doesn't it? And you can see that the roof has a hole in the top.

Very interesting when it comes to thinking about acoustics, but we'll get to the stadium later.

Okay, let's get started.

You're going to need a pencil and a pen, a ruler and a notebook.

Go and pause the video and get your things now.

Oh, I'm so excited for my star words today.

My turn, your turn.

Star words, star words, star words.

Good job.

You guys are ready as well.

Acoustics.

Your turn.

Let's say that word again.

Acoustics.

Your turn.

Good job.

Now, acoustician.

Your turn.

I'll make that bigger.

Acoustician.

Your turn.

I wonder what can you see that looks similar about those first two star words.

Have a look and tell your screen.

Well done.

They both look like the word acoustics.

Now an acoustician.

When a word has C-I-A-N, cian on the end, that means that it's somebody's job like a musician or an optician.

So an acoustician studies acoustics.

Let's go on to the next one.

Atmosphere.

Your turn.

Atmosphere.

Your turn.

Well done.

I love your actions today team, well done.

The next word is taut.

My turn, your turn.

Taut.

Taut.

Taut is like tight.

Taut is like.

Well done.

The next word is amplified.

Your turn.

Amplified.

Your turn.

And last word.

You've seen this one before team.

This word is absorbed.

Your turn.

Absorbed.

Your turn.

Well done.

We've done our star words, now let's have a look at what acoustics actually are.

Like we've talked about an acoustician is somebody who studies sound and vibrations.

They look at the vibrations in different atmospheres and then they decide what the best acoustics would be in order to create the best sound.

What were the letters on the end of this word that shows that it's somebody's job.

Can you tell your screen? Well done.

C-I-A-N an acoustician.

If an acoustician wants to make a loud sound and wants to amplify the sound very loud, they would use hard and flat surfaces.

If you think about glass and you think about a window, any sound that hits that glass window would be bouncing back very easily, so be very loud.

Can you tell me another surface that you can think of that is hard and flat.

Have a look around your room that you're in at the moment.

Maybe you're in your class, maybe you're in your home.

What surface can you see that's hard and flat? Can you tell me what you've seen? Well done.

Some of you have said the wall, some of you said mirrors as well.

They are hard and flat surfaces or even a tabletop.

In this image, you can see it is a concert hall.

Can you have a look at the picture and tell me what are the walls made of do you think? What material? Well done.

It looks like they are wood.

Do the walls look hard and flat or do they look soft and squidgy? Well done.

They look hard and flat.

So would that make a loud sound or a soft sound? Tell your screen.

Well done.

That would make a loud sound so that the sound can be amplified.

Well done.

I want you to have a look at the picture and see which other surfaces apart from just the walls that you can see that are hard and flat that will amplify the sound.

Have a look at the video and tell the screen.

What can you see? If you're not sure, what can you see that the stage is made out of? Oh, well done, you figured it out.

The floor on the stage is also made of a hard, flat surface to help amplify the sound and you can see the musicians are sat on the stage.

So that will help to amplify the sound, to make it nice and loud, so that everyone in the concert hall can hear the music.

We've said that hard flat surfaces help to amplify the sound.

In the picture, there are some surfaces that do not look hard and flat.

Have a look at the picture and tell me what can you see that does not look hard and flat? Can you spot any soft and squishy surfaces? Have a look? What can you see? Pause the video if you need more time.

I wonder how many of you said the chairs.

The chairs might be made out of soft squishy material.

Some sort of fabric.

When you go to the cinema, what are the seats like in the cinema? Well done, they're nice and comfy, aren't they? And they're really squidgy.

So that helps to.

What was our star word? Absorb the sound.

Well done.

So soft and squishy materials.

Let's do soft and squishy absorb the sound.

Can you tell your screen with me again? Soft and squishy materials absorb the sound.

Now say it one more time without me.

Well done everyone.

I'm going to give you an awesome chair because you're working really hard today.

There is another soft and squishy thing in this picture and that's the people on the stage.

I am quite soft and squidgy compared to glass or compared to wood.

So humans also would absorb sound.

So if you fill a concert hall with people in the audience, that's also going to affect the sound because they will absorb the sound.

Let's have another look at another setting.

Have a look at this team.

Tell me what surfaces can you see in this picture? Well done.

Some of you spotted the windows.

Tell your screen.

Well done.

I wonder who has said the floor, that looks like it's made out of marble? Marble is very hard and flat.

Does that mean it will amplify the sound or absorb the sound.

Tell your screen.

Well done.

Have another look.

What are the chairs made out of? Can you tell your screen? Well done.

The chairs are made out of wood.

Wood is not very soft and squishy, it's very hard and flat.

So that will also amplify the sound, well done.

Now one more thing to look at.

What's about the roof? Have a look at the roof and tell me what you can see.

It's very beautiful, isn't it team? Well done.

Some of you have said it's very, very tall and you're absolutely right.

That will help to amplify the sound and then the roof is hard and it's got a flat surface which is curved, that will help to amplify the sound.

So team this church, do you think any sound made in here would be amplified or absorbed? What do you think? Can you tell your screen? Well done.

It would be very loud cause it would be amplified by the hard flat surfaces.

Good job team.

Let's have a look at our next one.

So soft and squishy, remember, does that amplify or does that absorb? That does? It absorbs the sound.

Well done.

Now this is a different theatre.

You can see lots of people.

How do you think the audience and the performers will affect the acoustics? Will they help to amplify or will they absorb the sound and make it quieter? Tell your screen.

Good job.

They will absorb the sound which will make the sound quieter.

An acoustician has done something and designed the room to counterbalance, which means to help the acoustics, so that it can still be amplified when there are people in the audience.

Have a look on which surface can you see has been built in order to amplify the sound here.

Well done.

All of the space at the back of the concert hall is hard and flat so there's the ceiling and also the walls around the performance is hard, flat wood which will help to amplify the sound even if there are lots of people in there.

Well done team.

I'm going to now show you an image and I want you to tell me what acoustics can you see.

Can you see soft and squishy materials that will be absorbing the sound or can you see hard flat surfaces that will be amplifying the sound? Have a look.

Pause the video and tell the screen what sort of surfaces you can see.

Well done.

I can see lots and lots of people in the crowd.

People we know are soft and squishy, so they are going to be absorbing the sound making it quieter, well done.

What on earth are these coloured panels on the side? They look very interesting.

Do they look soft and squishy, or do they look hard and fat? Well done.

They look hard and flat.

So that will help to amplify the sound making it louder and I can see that they're at a live music venue.

So they'd want it to be nice and loud so they can hear the DJ's music.

The other thing that's interesting about this image team is that there is no roof.

There's a few streamers at the start, but then it is open.

What do you think an open roof will do to the acoustics here? Will it amplify or will it absorb? What do you think? Can you tell your screen? Well done.

I wonder what you said.

It will absorb because the vibrations of the sound will go through the roof and out and they will not bounce off the hard flat surface because there is no hard flat surface cause the roof is open.

So it's very similar to my background of this stadium.

You can see that the roof is open, so all of the vibrations, the sound from the crowd or any speakers, all of that sound will go through the roof and that will make it quieter.

But you don't want it to loud, remember because if there's that many people in the crowd, it's going to be very noisy.

So you have to have a balance.

Have a look at the table.

You can see on the left hand side, in fact, I'll make it bigger.

On the left hand side are some different venues.

Let's read them together.

So let's start with the pink in the top left hand corner, recording studio, concert hall, sports stadium and headphones and speakers.

On the right gives a description of what an acoustician would want the sound to be like in each venue.

But they're all jumbled up, so you need to match them together.

Let's read them first and then I want you to pause the video and match up with the venue.

Let's start with the top right hand corner, the purple.

Make the best quality sound possible.

To block out sound from outside the room.

To make sound be heard from a long way away.

To make the sound as loud as possible.

The first one, make the best quality sound.

Where would you want the best quality sound? Recording studio, concert hall, sports stadium or headphones and speakers? That's a tricky one, isn't it team? Because you want the sound to be good in all of those places.

This one I'm going to give you a clue.

If you are listening to music very close to your ears, you want the sound to be very, very good, because it's so close, then you'll hear it really, really well.

I wonder if that's giving you a clue.

Can you tell your screen what you think it is? Well done.

Headphones and speakers.

You want to make the best quality sound possible.

So now, with the last three, I want to match up to the venue.

Pause the video and write out your table in the correct matches now.

Well done.

Pause the video if you haven't finished.

So let's have a look at the answers.

I've matched up the colours with the correct answer.

So the blue, headphones and speakers, you want to make the best sound quality possible.

The pink, recording studio, you want to block out sound from outside the room because you don't want any extra sounds on your recordings, otherwise, that will ruin your recording.

In a concert hall, you want to make the sound to be heard from a long way away.

For instance, if there's a quiet flute or violin, even the person at the very back of the concert hall wants to hear what they're playing.

And then in a sports stadium, you want to make the sound as loud as possible.

I wonder, why do you think you want it loud in a sports stadium? Can you remember what I said when I talked about my stadium? Because you wants it to be really exciting, don't you? If you're at a sports match that you're watching or you're maybe at a live music concert in the stadium, you want it to be really loud, so it's really exciting.

Now we want to talk more about stadiums. I'm going to show you three examples of stadiums with different acoustics.

The first one on the screen is a stadium with no roof.

A little bit like the one in my picture, but not quite because there is no roof at all.

So it's completely open.

So it's just the seats on the side.

Can you tell your screen and have a think about what the acoustics will be in this picture? Well done.

Use the arrows on the picture to help you.

What will be bouncing off? Good job.

The sound will be bouncing off the sides from the seats.

If there are people there, though, that will absorb the sound.

If there's no roof, will that help it to amplify or absorb? Well done.

It will absorb into the air because they will not be amplified back from the roof.

Do you think this will be a loud stadium, will it be as loud as possible? Or will it be a little bit quiet? What do you think? Well done.

It will be a little bit quiet because the seats will absorb if there's people sat in them and then because there's no roof, it will not be amplified back into the stadium.

Let's have a look at the next one.

So this looks very similar to the stadium behind me, doesn't it team.

So there's a small roof over this section of the stadium.

So just like before, you have the seats, but this time there is a hard flat surface part of the roof.

What will that do to the sound? Can you tell your screen? It will.

Well done, it will amplify the sound.

Will it completely amplify it with a full roof or just partly amplify the sound? What do you think? Well done, it will partly amplify it because it's only part of the roof that is a hard flat surface.

Is this as loud as you think it could be? No, it's not.

It could be louder.

How could we make this stadium even louder? Can you tell your screen? Well done.

You could put a hard flat surface completely covering the roof.

Let's have a look.

If you have a roof on the stadium, this hard flat surface, the vibrations of the sound will bounce back and it will make it very amplified, so very loud.

This might make it too loud, like I talked about with my stadium in my background.

If this roof was covered and there were all of these people here, I think it would be too loud.

So they had to open the roof so that it's not too loud and we know what happens.

We talked about it in last lesson.

What happens if a sound is too loud? What can it do to your ears? Good job.

It can damage your ears, so you have to be very careful.

I'd like you now to write out what you can see in the last diagram.

We've not done much writing yet this lesson cause I've got a task at the end.

But here's your first writing task of the lesson.

I'd like you to finish my sentence using the word loud or soft and then I'd like you to explain why using your knowledge of acoustics that we've learned about so far this lesson.

Pause the video and write out your two sentences now.

Well done.

In this diagram, I can see that the sound will be loud.

This is because the roof is a hard flat surface.

So it is amplifying the sound.

Give yourself a tick or edit your answer if you want to add some more detail.

Well done everyone.

So now I have a task for you.

I want you to design me a classroom.

I want you to draw your classroom like the diagram of the stadium.

But this is the criteria for this classroom that I want you to design.

You have to imagine that you are now an acoustician.

You're a scientist who studies sound and vibrations.

However, in my classroom, I don't want to hear anyone walking down the corridor outside.

The room can't be too loud if we're all talking or if we're singing cause I like doing lots of singing with my class.

So I'm going to need some soft squishy material in there, so that it absorbs some of the sound.

But I also need to be able to hear the children talking, even if they're on the back row.

Do you think you're up for the challenge? I said, do you think you're up for the challenge? Well done.

I would like you to design your classroom using this criteria.

Pause the video and complete your task now.

Well done everyone.

I wonder what your classrooms look like, I bet they're all different.

Now we're just going to do a very brief experiment, which is about protecting our ears.

Because we've talked about amplified sounds being very, very loud, if there is not enough material to absorb.

When we protect our ears, what do you think that does to the vibrations? If we protect our ears? Well done.

It stops the vibrations getting into our ears and that is why it would be very loud.

So what can you do to protect your ears.

Can you have a think? Well done.

You could cover your ears.

Would it be enough to just put my hands over my ears? Can you still hear me? Go and put your hands over your ears? Does it sound different? It does a bit, doesn't it? Take your hands away from your ears now.

Now we don't want to put our fingers in our ears cause that's dangerous and you might damage your ears cause they're very, very delicate.

You can put your hands over your ears to protect your ears from loud sounds.

I wonder, have you ever done that when there's big fireworks in the sky and suddenly it gets really loud or if a siren goes past on the road.

And I don't like it because sometimes it gets very loud.

So what we can do is we can cover our ears.

The best way to protect your ears though is to get your headphones, some protective headphones that cover your ears.

Let me just get mine.

These are my headphones and these will protect my ears from any sound that's too loud.

Can you remind me, why is this protecting my ears? I can't hear you.

Well done.

Because the vibrations are stopped from getting into my ears.

So do you remember in our last lesson on sound, we looked at the aeroplane guiders who guide aeroplanes in to park.

It's very loud because of the engines, so they have to wear protective headphones.

Tell your screen.

What do you wear if you want to protect your ears? Well done.

You need to use protective headphones.

If I wore a hat, would that protect my ears? No, it wouldn't.

If I wore a scarf, would that protect my ears? No, it wouldn't.

Why would a scarf not protect my ears? Good job.

Because it's not covering my ears, so it's not preventing the vibrations from getting into my ear canal.

I wonder if you could design and make your own protective headphones if you wanted to have a go.

Think about the material that you'd want to make them out of.

Well done everyone.

I wonder if you wanted to share your work with me.

You can ask your parents or carers to share it on Twitter.

I would love to see your designed classrooms. Well done everybody.

Bye.