Describe how the loudness and frequency of a sound are represented in the vibrations of the eardrum, and explain why very loud sounds can cause permanent hearing damage.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (5 marks)
The eardrum vibrates with an amplitude that is proportional to the sound intensity – louder sounds give larger amplitude vibrations.
The eardrum vibrates at the same frequency as the incoming sound wave – the frequency of the vibration matches the sound frequency.
When a sound is very loud the eardrum and the ossicles are forced to vibrate with a very large amplitude.
These large amplitude vibrations can damage the hair cells in the cochlea.
Because hair cells do not regenerate, the damage is permanent and hearing is permanently reduced.
The eardrum vibrates at the same frequency as the incoming sound wave – the frequency of the vibration matches the sound frequency.
When a sound is very loud the eardrum and the ossicles are forced to vibrate with a very large amplitude.
These large amplitude vibrations can damage the hair cells in the cochlea.
Because hair cells do not regenerate, the damage is permanent and hearing is permanently reduced.
Examiner tips
- Use the terms ‘amplitude’ for loudness and ‘frequency’ for pitch; link each to eardrum vibration.
- Show the causal chain: loud sound → large amplitude → hair‑cell damage → permanent loss.
- Include the point that hair cells cannot regenerate to justify permanent damage.
Common mistakes
- Confusing loudness with frequency or using ‘volume’ instead of amplitude.
- Failing to mention that hair cells cannot regenerate, so damage is permanent.
- Giving a generic explanation of damage without linking it to eardrum/ossicle vibration.
Mark scheme (5 marks)
- The amplitude of eardrum vibration increases as loudness (sound intensity) increases
- The frequency of eardrum vibration matches the frequency of the incoming sound wave
- Very loud sounds cause the eardrum or ossicles to vibrate with very large amplitude
- These large amplitude vibrations can damage the hair cells in the cochlea
- Damaged hair cells cannot regenerate / are permanently lost, so hearing is permanently reduced
Key terms in this question
Related
- All AQA A-Level Physics (7408) revision notes →
- How to answer a "Describe and Explain" question →
- Decode the mark scheme abbreviations →
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