Look at the objects below. What do they all have in common?
What one word connects all of these objects? Discuss with your partner before revealing.
What do they all do to produce sound?
By the end of this lesson you will:
Every sound starts with something vibrating.
When you strike a tuning fork, the prongs vibrate rapidly. These vibrations push air particles, creating a sound wave.
Touch a vibrating fork to water and you'll see it splash — proof of the vibration!
Copy this definition:
Sounds are made when an object vibrates. A vibration is a rapid back-and-forth movement. The vibrating object pushes nearby air particles, creating a sound wave that travels to our ears.
Match the object to the part that vibrates:
| Object | What vibrates? |
|---|---|
| 🎻 Violin | The strings |
| 🗣️ Voice | The vocal cords |
| 🔊 Speaker | The cone |
| 🥁 Drum | The skin |
In your notes: Identify what vibrates for violin, voice, loudspeaker, drum and trumpet. Write in full sentences.
Then add 2 more examples of your own.
In your notes: For violin, voice, loudspeaker, and drum — explain what vibrates and how the vibration is started.
Challenge: How does a loudspeaker convert an electrical signal into a sound wave? Use: vibration, cone, air particles.
Sound needs particles. No particles = no sound.
Sound is a longitudinal wave. It makes particles vibrate and bump into their neighbours, passing energy along.
Copy into your notes:
Sound travels fastest through solids (particles closest together). It travels slowest through gases (particles far apart). Sound cannot travel through a vacuum because there are no particles to vibrate.
This famous experiment proves sound needs a medium to travel.
Air inside → Sound can be heard ✓
The bell keeps vibrating but with no particles, the sound can't reach your ears.
Apply what you've learned about how sound travels.
Fill the gaps using the word bank:
1. Sound travels fastest through a solid because particles are closest together.
2. Sound travels slowest through a gas because particles are furthest apart.
3. Sound cannot travel through a vacuum because there are no particles to vibrate.
In your notes, answer in full sentences:
1. Draw the arrangement of particles in a solid, liquid and gas.
2. Explain why sound travels fastest through solids.
3. Explain why a bell in a vacuum cannot be heard.
Starter: "The sound cannot be heard because..."
In your notes, write detailed paragraphs:
1. Compare how sound travels through solids, liquids and gases. Use: particle arrangement, vibration, energy transfer.
2. Explain the bell jar experiment fully.
3. Astronauts can't hear each other in space. Explain why, and how touching helmets together would help.
Extension: Is human hearing better or worse than most animals'? Research one animal and compare.
We can visualise sound waves using special equipment.
A signal generator creates the signal. A loudspeaker makes it audible. An oscilloscope shows the wave shape.
Copy into your notes:
An oscilloscope lets us "see" sound waves on a screen. The display shows a transverse wave shape, but sound is a longitudinal wave — the oscilloscope is a representation.
Adjust the sliders to explore how amplitude and frequency change the wave:
How loud a sound is depends on the height of its wave.
The amplitude is the distance from the centre line to the peak. Larger amplitude = louder sound.
Small amplitude
Large amplitude
Copy into your notes:
The amplitude is the height from the centre line to the peak. Larger amplitude = louder sound. Smaller amplitude = quieter sound.
Which is louder? Tap to check.
How high or low a sound is depends on how many waves there are.
The frequency is how many waves pass a point per second, measured in Hertz (Hz). Higher frequency = higher pitch.
Few waves = low frequency
Many waves = high frequency
Copy into your notes:
The frequency of a wave is the number of waves per second, measured in Hertz (Hz). Higher frequency = higher pitch. Lower frequency = lower pitch.
Key definitions:
• Peak — the highest point of a wave • Trough — the lowest point
• Wavelength — distance from peak to peak • Amplitude — height from centre to peak
Which wave has the higher pitch? Tap to check.
Use your knowledge of amplitude, frequency, pitch and loudness.
Copy the diagram above and match these definitions:
Peak = the highest point of a wave
Trough = the lowest point of a wave
Wavelength = distance from peak to peak
Amplitude = height from centre to peak
Draw and label a wave (peak, trough, wavelength, amplitude). Then describe:
This sound is getting...
This sound is getting...
Use: "This sound is getting _____ because the amplitude/frequency is _____."
Draw a reference wave. Then draw waves that show: (a) a quieter sound, (b) a higher pitch, (c) a louder sound, (d) a louder sound AND lower pitch.
For each, explain what changed (amplitude/frequency) and why it sounds different.
Look at the three patterns below, just like on a real oscilloscope.
Three sounds (A, B, C) produce these oscilloscope traces:
Answer these by choosing A, B or C:
Which pattern was made by a low-pitched note? A
Which came from the loudest sound? C
Which has the highest frequency? B
Answer in full sentences in your notes:
a(i) Which pattern was most likely made by a very low-pitched note?
a(ii) Explain your choice.
b(i) Which pattern came from the loudest sound?
b(ii) Explain your choice.
Answer in detailed paragraphs:
a) Identify the low-pitched pattern and explain using the term frequency.
b) Identify the loudest and explain using the term amplitude.
c(i) How would sounds A and B be similar?
c(ii) How would sounds A and B be different?
Challenge: Could two sounds have the same pitch but different loudness? Draw what this would look like on an oscilloscope.
Each wave below is changing. Describe what's happening to the sound.
For each wave, pick the correct description:
This sound is getting quieter
This sound is getting higher pitched
For each wave above, describe the change in your notes using this structure:
"This sound is getting _____ and _____. I can tell because the _____ is _____."
For each wave: describe both what is happening to the sound AND explain using the scientific terms amplitude/frequency. Include units (Hz) where appropriate.
Then explain: Why do sound waves lose amplitude as they travel further from the source? Link to energy transfer.
Close your notes. Try to answer from memory. Tap cards to check. This is where real learning happens!
Try to answer each question in your head before tapping to reveal.
Rate your confidence for each learning objective:
Describe how sounds are produced
Explain how sound travels
Describe pitch and loudness on an oscilloscope
Explain amplitude vs frequency
🔴 Not sure → 🟡 Getting there → 🟢 Confident
Return to your learning objectives and check them off. What do you now know?
Exit ticket — write in your notes:
Write one fact you learned today and one thing you want to know more about.
Make sure all of these are in your notes with definitions:
Homework Extension: Explain why you can hear your heartbeat through a stethoscope but not through open air. Use the terms: vibration, solid, gas, amplitude.