SoundFrom musical boxes to iPods

Supports National Curriculum, Key Stage 1: Unit 1F and Key Stage 2: Units 5F

Suitable for years 4,5 and 6.

The time for the basic session is about 1 hour but longer if activities 13,16,17,18, 22 are included. This can be varied by taking shorter paths through the material. Choices may depend on the apparatus available or the particular needs of the class.

Outline of contentAims to

- establish what the children already know, using an intriguing demonstration - establish that sounds needs a material through which to travel- show that vibrating objects are sources of sound and sound travels as a wave- demonstrate that sound can travel through metal, string, etc as well as air- associate the size of the vibrating object with the frequency produced through fun pictures,

activities and wind instruments- relate their knowledge to other instruments with which they are familiar - show that knowledge about sound has enabled scientists to develop ultrasound scans,

modern sound systems etc

Points to note:Please read the notes about safety and agree the assessment with the teacher before the session!

Cross References- The slides in the PowerPoint presentation are referenced in the table.- As the presentation may be running throughout the session some simple slides provide a

suitable background, alternatively switch to a black screen.- Apparatus details are provided and are linked to the relevant sections. - Notes about safety are included at the end of the document

Vocabulary: The presentation uses expressions included in the KS 1&2 strategies http://www.standards.dfes.gov.uk/schemes2/science/?view=get

Misconceptions to be correctedAir moves with the sound from the source to our ears.Sound can only travel through air.Sound is like light in that it cannot travel through opaque objects.When blowing a bottle - the more water the lower the pitch. The strings on violins etc are at very different tensions eg they expect the E string on a violin to be at a much higher tension than the G string.

Feedback from the trials:“Thanks for the lesson on sound - the children loved it and were talking about it the next day - a good topic to teach due to the children's interest in sound.” “They 'loved' the graphics on screen of the animals and examples of musical equipment. They were fascinated by the practical demonstrations, which I personally believe is how children learn and acquire more knowledge more effectively.”“The children listened intently throughout and were very responsive.I thought the lesson was conducted excellently and the children were enthralled. The information provided was suited to the children’s learning ability (this is important).”

SoundFrom musical boxes to iPods

Activity Discussion Aims/factsShow Powerpoint Slide 1 should be showing as the class enters. (Some cheerful music could be playing - if this is convenient - switch it off before starting.)

1. DemonstrationHold up the drive mechanism of a musical box which is playing.Then touch the mechanism on a metal tray or metal tray. See Apparatus List

As you hold up the mechanism, ask what the children can hear. Only a few close to the front will hear anything. Once the mechanism is held against the tray the tune should then be heard loudly. Ask them to try to explain.

To catch the children’s attention and find out what they know.

2. Discussion Ask how they hear the sound.Discuss the sound being produced and then travelling to their ears.

Sound travels from a source to their ears.

3. Show Powerpoint Slides 2,3,4Explain that sometimes astronauts have to climb outside their spacecraft to make repairs. Point out that the earth can be seen so far away that the curvature of the horizon is clear. In slide 3 the space ship is reflected in the astronaut’s visor.

Point out that if someone shouts outside a house, the sound can be heard inside the house. Space ships have very thin outer skins. Ask whether, during a space walk, an astronaut could be heard by those inside the space craft. If they are not sure, point out that some of the pictures show the astronaut attached to a line. Ask what it is for. (For Communications and to prevent the astronaut moving away from the space ship and being lost.)

There is no air outside the space craft so the astronaut’s calls would not be heard by those inside the space craft. Sound needs something to travel through. (eg air )

4. Demonstration Show Powerpoint Slide 5

Use an Airzooker to send a waft of air across the classroom to blow the hair of some of the children.

See Apparatus List

See Safety Notes

Point out that there is air in the classroom and they can hear you speaking. Then ask the children whether they feel a rush of air when you speak. They will enjoy this and understand that sound does not travel with the air.Explain that there must be another explanation.

Conclude that air does not travel with the sound.

5. Class activity: ‘dance’

Ask about 10 volunteers to line up across the classroom all facing towards one end of the line. Child 1 should start to step. The as soon as child 2 sees child 1 move, 2 should start to step. As soon as child 3 sees child 2 move, 3 should start to step.

A second group could dance, if there is time. Show Powerpoint Slide 6

See Apparatus List

See Safety Notes

The remainder of the class should watch and explain what they see. The line should automatically form bunches which move along the line to represent the sound travelling. Point out that the children do not move along the line. Only the bunches move along: the individuals just vibrate.Ask them how the dance could represent quiet sounds and loud sounds.

As the sound travels, the individual particles vibrate and do NOT travel with the sound.This is called a sound wave.

6. Discussion A sound wave travels

Show Powerpoint Slide 7

When the alarm rings we do not feel a rush of air. The sound wave travels from the alarm to our ears.

from the source to our ears.

7. DemonstrationSinging rod

Hold the rod lightly with two or three fingers at its mid point and then with the other hand rub the rod slowly from the centre outwards in slow sweeping movements. The rod will vibrate and sound a note. The vibrations are longitudinal. If the end of the rod is pointed towards the class they will hear a louder sound.

See Apparatus List

Ask the class to hum gently and to feel their throats at the same time.

Invite the children to touch the end of the rod and feel the vibration. This is not felt along the rod only at the end showing the rod is vibrating longitudinally.

(A rod made of a different material or of a different length will produce a sound of a different frequency and can be used in later activities if available.)

Ask what they feel and explain that these are vibrations. They may have done this in at KS 1, but it is a quick way for them to learn what vibrations are.

Vibrating objects produce sound.

8. Quiet sounds

Ask them to be very quiet and try to make no sound at all. They quickly find that they need to be very still. Sounds outside the room such as traffic seem loud.

After a moment someone will move and make a chair squeak or drop something, which will sound loud. When they are very still, ask them to start to make very quiet sounds – they must not speak!They find they need to move and perhaps tap something.

Reinforce that sounds are made when things move.To make quiet sounds small movements are needed.

9. Loud sounds

If you think they will behave well you could make a pact that they will go quiet when you raise your hand. Then ask them to make loud sounds- without speaking.

They will find that loud sounds are associated with large movements.During discussion link this with vibrations.

Loud sounds are made by large movements

10. Discussion about listeningShow Powerpoint Slide 8

Ask them to describe the kitten’s ears. They are large and point forward. The cat is able to detect very quiet sounds because the large ears collect sound waves over a wide area. The ears point forward so the kitten turns its head or its ears to hear where the sound comes from.

Some animals can hear very quiet sounds

11. ActivityThe ends of the sound tubes should be placed over the ears of a volunteer. Then the tube tapped and the volunteer asked which side the sound comes from.

See Apparatus List

Human ears are on the sides of the head with small ear flaps that point slightly forward. The ears detect the sound and send messages to the brain. The two ears send different signals so we know from which direction the sound is coming.

Human hearing is very sensitive to direction.

12. Extra Show Powerpoint Slide 9Absorption of sound(note the kitten is much younger in this picture than in slide 9)

Ask why the kitten is looking unhappy?They will suggest that it does not like the hat. Then ask if they think it will still be able to hear.This can lead into a discussion about soft materials absorbing sound which would link well with investigation work that the teacher may be planning.Point out that because the hat is thin it will not absorb all of the sound.

Soft materials absorb sound.

13. Discussion Ask them whether they can swim underwater. Sound will travel

Show Powerpoint Slide 10

The whales communicate with a sort of song. They make the sound underwater and it travels long distances through the water.(Beluga whales are very social and make a wide variety of sounds.)

Ask whether they can hear if the side of the swimming bath is thumped when they are underwater.They may point out that they do not hear voices above the water well. Explain this is because the sound does not pass through a change of material well. This will be useful when explaining ultrasound.

through water.

14. Activity Tunes from a coat hanger

See Apparatus List

Use a coat hanger with a piece of string tied at each corner as shown in the apparatus list.Show the Marvin cartoon on Show Powerpoint Slide 11 after the volunteer has reported what was heard.

See Safety Notes

Ask for a volunteer. Wrap the ends of the string round a finger of each of the child’s hands. Then say ‘Now put your fingers in your ears’. Tap the coat hanger gently with a metal object. Ask whether the sound was loud. Tap again without the fingers in the volunteers ears. Discuss the difference in the loudness. Explain that the sound travels through the metal and string more easily than through the air.

15. Extra - Bush Telephone Show Powerpoint Slide 12

See Apparatus List

Ask a child to take one cup as far as the string will allow across the classroom. Child 2, who should be close to the front of the class, should hold the second cup again an ear. Arrange that the string is held taut. Blindfold child 2 with a soft dark scarf. Then hold up a card showing a simple message. Ask child 1 to whisper the message into the cup and then ask child 2 what is heard.

This activity can be expanded by having a few cups linked together by taut string and then the message should reach children 2, 3 etc.

Child 2 should hear the message clearly

If a child takes hold of the string the listener will not be able to hear. Also if the string is slack nothing is heard.

Make sure that the children understand that the sound travels through the string. They might notice that the message can be heard very quietly close to the string – but not nearly as well as via one of the cups.

Sound will travel through string and other materials.

Sound does not only travel through air.

16. Extra Telephones Show Powerpoint Slides 13,14

A very simple diagrammatic explanation of a telephone is provided. Explain that the sound is changed into an electrical signal by a microphone in a sound system – the information travels as an electrical signal through amplifiers etc to a loudspeaker. A loudspeaker or earpiece changes the electrical signal back into a sound message. A telephone works in a similar manner.

This has been included in response to questions from children during the trials.

The idea that the message can travel as an electrical signal can be linked back to human hearing. Point out that when sound reaches our ears then message is sent to our brain as an electrical signal.

17. Extra Show Powerpoint Slide 15

The children ask lots of questions and this is an opportunity to link the science with their

Mobile phonesThere is an extra stage in the communication with the sound changing to first an electrical signal then to a radio signal.

everyday experiences.

18. Discussion Show Powerpoint Slides 16,17,18Link low notes and low pitch and also link high notes and high pitch. (The children who play instruments may know the word pitch)

Ring a small bell when you show Show Powerpoint Slide 19 and ask whether the large bell would make the same sound.

See Apparatus List

Ask what noise a cow makes. They will enjoy making moooo sounds. Then ask what sound a baby mouse makes. They will squeak. They will know that the cricket makes sounds by rubbing their legs (knees) together to produce an even high pitch sound.Bring out – large objects make low notes and small objects make high notes.The large bell is in Siena, Italy. Ask what sound the large bell will make. Discuss the difference between the bells.

Large objects usually produce low pitch sounds. Small objects usually produce high pitch sounds.

19. Straw Oboes Show Powerpoint Slide 20

Ask 2 children to give each child one straw. Prepare the straws as on the apparatus list. Explain that they should blow the cut end to make a sound. Ask them to put up their hands when they make a sound. It is often children who have not contributed much who make the sounds first. Encourage them to keep blowing and snip about 2 cm off the end of the straw. Repeat this so that the class hears the note increase in pitch.

See Apparatus List

This is a good activity to catch the interest of the children who have not answered questions so far. Once a child can make the sound, raise your hand for silence and ask the child to come forward, then snip the straw quickly about 1 cm at a time. Some groups may be able to cut the straws – but this approach ensures they all hear the increase in frequency.

Summarise the discussion using slide 21.Large things make low pitch sounds.Small things make high pitch sounds.

20. Introduce the word frequency. Show Powerpoint Slide 22

Slide 23 provides some extra examples for discussion.

Low pitch = low frequencyHigh pitch = high frequency

21. Class Activity (Could be omitted)

Give out plastic bottles part full of water to volunteers in each class group. Ensure that each group has similar bottles with different quantities of water in them.

See Apparatus List

Show the children that if you blow across the neck of the bottle a note is produced.

See Safety Notes

Children find this quite difficult but fun. They notice that the more air in the bottle the lower the sound.

Lead into the next demonstration.

Bottles with different amounts of air in them produce different sounds.

22. Manometer demonstrationBlow across the neck of the bottle attached to the tubing in order to make a note. Ask the teacher accompanying you to raise and

Discuss what is changing as the note changes.

Point out that wind instruments are blown.

The more air in the bottle, the lower the frequency. The less air in the bottle, the higher the

lower the reservoir so that the amount of water in the bottle varies. The note produced can be varied to make a tuneful sound.

See Apparatus List

See Safety Notes

The discussion should provide an opportunity to ask which wind instruments the children are learning to play.

frequency.

23. Wind instruments

A ‘Swanee whistle’ makes an intriguing sound.

See Apparatus List

Children often play recorders.The lowest note on a recorder is sounded when all the holes are covered. Show how when the air column is effectively shortened- the frequency rises. If available show a soprano recorder that has ?? as the lowest note and explain that the vibrating air column is small – hence the higher pitch note.

Use any wind instruments that are available to reinforce the ideas covered so far.

The longer the air column, the lower the note.

24. Stringed instruments Show Powerpoint Slide 24

Show a violin or other string instrument and point out that the strings are the same length but make different sounds.

See Safety Notes

Ask the children to show their stringed instruments. Ask what else they notice apart from the length. Some will spot that the strings are of different thicknesses. Link with size.Those who play a stringed instrument will know that the note can be varied by changing the tension.Point out this can be used for tuning.

The thicker the string the lower the frequency.Shortening the length increases the frequency.Link both to previous ideas.

25. Elastic box

Stretch a length of fishing pole elastic and pluck it. The sound will be very quiet.

Clip one need of the fishing elastic to one edge of a metal box. Stretch the elastic across the box and pluck it. They should hear the sound clearly. This is a good opportunity to link back with the musical box movement.

See Apparatus List

Stretch the elastic round the box a few times increasing the tension each turn. Secure the elastic with a bulldog clip or round your finger and then pluck each turn separately. The tighter the elastic the higher the note.

See Safety Notes

Bring out from the discussion the need for a sound box for string instruments. Point out that electric guitars do not have a sound box but use electronic systems to amplify the sound.

(This could be extended into an investigation for another occasion. The children could stretch elastic bands across a food container and observe that changing the tension, thickness or length changes the frequency.)

The tighter the elastic the higher the frequency

26. Revise ideas so far

Show Powerpoint Slide 2527. Sound systemsExplain that sound systems have loudspeakers which vibrate and cause the air to vibrate.

Headsets vibrate a small amount of air so have to be placed close to one person’s ears. Large loudspeakers cause large vibrations in large amounts of air so the sound travels to many people.Link with Radio, CD players, iPods etc

Use to reinforce ideas.

28. Ultra soundShow Powerpoint Slide 26, 27Ask if they can spot the baby.

Ask who has a dog. Then whether they have dog whistle. Ask why it would have not been very useful if you had brought one. They will know that the dog whistle sounds a very high note that humans can hardly hear at all. Explain that if very, very high frequency sound is produced it can be used to ‘see’ inside people. They will ask whether the picture is like an x-ray. Explain that the sound bounces back off surfaces so it bounces back off the baby to build up a picture.

Ultrasound is used to see inside people and can see babies before they are born. Explain that knowledge about sound has made it possible for scientists to develop ultrasound scans. Doctors use the scans when caring for people.

29. SummaryShow Powerpoint Slide 28Go through the list of uses of sound and its applications.

Explain that scientific knowledge about sound has made it possible for iPods etc to be developed.

Physics is everywhere.Powerpoint Slide Slide 29

Apparatus for Sound Presentation

Ask the teacher to arrange for musical instruments to be available. Some children will be able to bring instruments that they are learning to play into school.

1. Demonstration Music box movement

available on line for about £4 Metal tray

4. Demonstration Airzooker (Available from online shops which sell ‘gifts, novelties and stocking fillers’.)

5. Activity Dance steps About 10 children should be in line one behind another, spaced across the classroom.

StartRight foot forward

Left foot forward

Right foot back

Left foot back

Right foot back

Left foot back

Right foot forward

Left foot forward

Repeat

Child 1 starts to step as shown in the diagram. Child 2 starts to step after child 1 has taken the first step. Child 3 moves once child 2 has started etc

7. Singing rod A length of smooth solid metal rod, e.g. a 1 metre length of aluminium rod works well.

(Available from large DIY stores) String-player’s rosin block and soft cloth (eg duster)

Rub the cloth on the rosin block.Hold the rod at XX with two fingers and the thumb of one hand. Rub the rod with the cloth, slowly and gently from the centre towards the end of the rod.Repeat until the sound is quite loud.

(If rods of different lengths or different materials are used then they will produce different frequencies and can be used to support the work on varying sounds which comes later in this presentation.)

11. Activity

X

X

2 sound tubes (pocket money toys which wail when whirled around – from toy shops)Two sound tubes should be joined together with tape. One end should be placed over each ear of a volunteer with the tubing behind the head. Then the tube should be scraped or tapped at any point. The volunteer will be able to say which side of the join the sound was made even very close to the join. This works even if the tubes are twisted.

14. Tunes from a coat hanger Wire coat hanger Two lengths of string A fork

More cartoons are available at: http://www.physics.org/interact-wide-template.asp

15, Extra - Bush telephone 2 (or more) paper or plastic cups String

Pierce a hole in the base of two cups. Pass string through the holes and knot the ends. More cups can be attached by extra strings.

19. Straw oboes straws (need to be straight – cut off the bendy bits if there are any)

o enough for one per child scissors

Flatten one end of the straw ~2cm from the end to the tip.Make two cuts in the now flattened end of the straw, to form a triangular tip. Insert the triangular tip of the straw into your mouth and blow hard. NB Prepare one per child before the session.

Back of head

tape

21. Bottles activity A collection of plastic bottles. Spare bottles which can be filled with water on arrival and that can be used to top up the

water. Note: If you are unable to collect a good number of bottles, check with the teacher because many children have their own drinking bottles in school. If you warn them before the lesson they could have different amounts of water in them ready for this activity.

22. Manometer Two 3 litre plastic ( lemonade or similar) bottles A and B Note: the stopper for A is needed! Length of plastic tubing ~1 metre long

(obtainable from large DIY stores) A cork which fits the neck of a bottle and has a hole bored in it wide enough for the tubing to

pass through tightly. Adhesive Approximately 2.5 litres of water. (A drop of food colour makes the liquid more visible.)

Assembly:(This proved to fascinate the children and was worth the effort of constructing it.)

Bore a hole in the base of A and fasten a length of plastic tubing into it. Use any suitable adhesive available and cover the joint with strong adhesive tape to prevent movement. Note: if the joint leaks slightly, a small bright cloth tied around the tube will stop it dripping.Cut the base off bottle B and smooth the cut edge.Use the cork to secure the tubing into the neck of bottle B.

Demonstration:Ask the teacher to hold bottle B You hold bottle A (without the stopper on) and pour about 2.5 litres of water into B. Blow across the neck of A and ask the teacher to raise and lower B so that the note changes.When the demonstration is over, raise B so it empties and the water fills A.Fasten the stopper tightly on A and invert A. The water can be removed after the session.

23. Wind instruments Swanee whistle - Available online from about £2 Borrow other wind instruments. Recorders are good because it is obvious that the lowest note

is sounded when all the holes are covered. The lowest note played by a descant recorder is C.

Details of recorder fingering at http://www.hants.gov.uk/hrs/finger/cfinger.html

Bottle ABottle B

Plastic tubing

Water

25. Elastic + Box Large metal biscuit tin or similar box Fishing pole elastic - This is brilliantly coloured elastic which is very strong.

(obtainable from angling shops - about £1.50 for several meters or sold by length.) Bulldog clip or similar.

Use the bulldog clip to fasten one end of the elastic to the edge of the box. In front of the children wind the elastic round the box four or five times increasing the tension each turn. Then pluck each strand of elastic.

Safety Notes

During the dance, children should be warned to take small steps so they do not tread on each other’s feet. Good behaviour is essential. Any child who is uncooperative should be sent from the line.

Singing rod: this can produce a loud sound. If the children appear uncomfortable then do not excite the rod further. Rosin, particularly when powdered, is a sensitizer which can give rise to allergic dermatitis. It is safest to put the rosin in a cloth and then rub the rod with the part of the cloth carrying the rosin. The children should NOT touch the rod which has been rubbed but the end should be safe enough.

The Airzooker can send a blast of air which surprises a child near to the speaker. Use it first to send a blast of air to those furtherest away from you.

Sound tubes: once joined these are long and should not be whirled around near the children. Tunes from a coat hanger: warn children of the danger of putting objects in the ear. Straw oboes and plastic bottles: for hygiene reasons the straws and bottles should not be

passed from child to child. Manometer experiment: if the apparatus leaks slightly, it should not be demonstrated near

electrical equipment. Loud sounds can damage ears. The children’s ears are much more sensitive to high pitched

sounds than an adult’s ears. Therefore if any high pitched sounds are produced, they must not have a large amplitude.

Elastic box: this should be demonstrated. Fishing pole elastic is strong but care needs to be taken when it is stretched. If over-stretched, it may break and flick back painfully. If this is considered a significant risk, eye protection should be worn by the demonstrator and the children should not be too close. Similarly, care should be taken if the tension of strings on stringed instruments is changed.

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