Hearing sound
I can explain how sound waves cause sounds to be heard, and describe the range and limits of human hearing.
- Year 9
Hearing sound
I can explain how sound waves cause sounds to be heard, and describe the range and limits of human hearing.
Lesson details
Key learning points
- Sound waves cause our eardrums, tiny bones within our ears, and the cochlea to vibrate.
- Specialised cells in the cochlea sense vibrations and cause electrical signals to be sent to the brain along a nerve.
- The brain creates the sensation of hearing a sound when it receives signals from the ear through a nerve.
- Human ears can detect sound waves with frequencies between 20 Hz and 20 kHz, being most sensitive to 2–5 kHz waves.
- Sound waves below 20 Hz are called infrasound; above 20 kHz, ultrasound. They are not detected by human ears.
Keywords
Sound wave - a ‘pulse’ that travels through a material, caused by forward and backward vibrations of particles
Eardrum - a membrane within the ear that is caused to vibrate by incoming sound waves
Sound - a sensation of hearing something
Amplitude - a measure of how far particles vibrate in a sound wave
Frequency - the number of vibrations each second
Common misconception
Sound waves are the same thing as the sound heard. Sound waves somehow 'have' sound.
Distinguish between the sound heard and the sound wave. The brain creates the sensation of hearing a sound when it receives nerve signals from the ear. The sound (heard) does not exist until created by the brain. Sound waves themselves have no sound.
Equipment
signal generator, speaker and connecting wires
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of the following describes the particles in air when there is no sound wave passing through?
Q2.What happens to the particles in air when a sound wave passes through?
Q3.Which of the following is the most accurate description of a sound wave?
Q4.Which of the following words can be used to describe a region of a sound wave in which the particles are closer together than normal?
Q5.A very loud sound is made, and the sound wave hits a small feather which is hanging from a thread. What happens to the feather?
Q6.Which of the following statements about sound waves are correct?
Assessment exit quiz
6 Questions
Q1.Match the following words with the correct definitions.
Q2.The diagram shows a human ear. Match each label with the name of the part.
Q3.Which of the following statements about a sound wave is correct?
Q4.Match each of the following types of wave with the correct frequencies.
