A-Level · Physics · AQA · Mark scheme decoded
AQA A-Level Physics: Simple Structure of the Ear and Transmission Processes — mark scheme explained
The short answer
The human ear is a complex organ that plays a crucial role in our ability to hear sounds. Understanding its simple structure and the transmission processes involved is essential for grasping how we perceive sound.
The question
Label the parts of the ear in the diagram below: [Diagram with unlabelled parts]
[Paraphrased for study — not reproduced from any exam paper.]
Mark scheme, decoded
How the examiner actually awards the marks on this topic.
Gradora's own decode of the marking approach — not the exam board's published mark scheme.
How marks are awarded
For descriptive questions, ensure you cover all relevant parts of the ear and their functions. For explanatory questions, focus on the step-by-step process of sound transmission. In labeling diagrams, be precise with your labels and use correct terminology.
What the command words demand
- Describe
- Provide a detailed account of the structure and function of the ear.
- Explain
- Give reasons or causes, showing understanding of how things work.
- Label
- Identify and name parts of the ear in a diagram.
- Identify
- Recognize and name specific structures or processes.
Model answer
A full-mark response to the question above, worked through step by step.
Timing: Allocate about 5-7 minutes for a 6-mark question to ensure you have enough time to provide a detailed and accurate response.
- Identify the visible part of the ear (pinna).1 mark
- Locate the external auditory canal, which leads to the eardrum.1 mark
- Find the three small bones in the middle ear (malleus, incus, and stapes).1 mark
- Label the oval window where vibrations are transmitted to the cochlea.1 mark
- Identify the cochlea in the inner ear, containing fluid and hair cells.1 mark
Final answer: [Diagram with correctly labelled parts]
Work through every step correctly and you earn all 5 marks.
Another worked example
Explain how sound waves travel from the outer ear to the brain.
- Sound waves enter the external auditory canal and reach the eardrum, causing it to vibrate.1 mark
- The vibrations are transmitted through the ossicles (malleus, incus, and stapes), which amplify them.1 mark
- The amplified vibrations cause the oval window of the cochlea to move, creating waves in the fluid inside the cochlea.1 mark
- These waves stimulate hair cells on the basilar membrane, converting mechanical energy into electrical signals.2 marks
- The electrical signals are sent to the brain via the auditory nerve for interpretation as sound.1 mark
Final answer: Sound waves enter the external auditory canal and reach the eardrum, causing it to vibrate. The vibrations are transmitted through the ossicles (malleus, incus, and stapes), which amplify them. The amplified vibrations cause the oval window of the cochlea to move, creating waves in the fluid inside the cochlea. These waves stimulate hair cells on the basilar membrane, converting mechanical energy into electrical signals. The electrical signals are sent to the brain via the auditory nerve for interpretation as sound.
Work through every step correctly and you earn all 6 marks.
Common mistakes
Confusing the pinna with the eardrum
Why it happens: Students often mix up the visible part of the ear (pinna) with the eardrum, which is not visible from the outside.
Fix: Remember that the pinna is the external part you can see, and it collects sound waves. The eardrum is inside the ear canal and vibrates in response to sound waves.
Forgetting the amplification role of the ossicles
Why it happens: The function of the ossicles can be overlooked, leading to incomplete explanations of how sound is transmitted through the ear.
Fix: Always mention that the ossicles amplify the vibrations from the eardrum, making them strong enough to move the fluid in the cochlea.
Misidentifying the parts of the middle ear
Why it happens: The names and functions of the malleus, incus, and stapes can be confusing.
Fix: Practice identifying each ossicle by name and function. The malleus is attached to the eardrum, the incus connects the malleus to the stapes, and the stapes transmits vibrations to the oval window.
Not understanding the role of hair cells
Why it happens: The conversion of mechanical energy into electrical signals by hair cells is a complex process that can be misunderstood.
Fix: Focus on how hair cells bend in response to fluid movement, generating action potentials that are sent to the brain via the auditory nerve.
Confusing the basilar membrane with the oval window
Why it happens: Both structures are involved in the transmission of sound waves, but their roles can be confused.
Fix: Remember that the oval window is where vibrations from the stapes are transmitted to the cochlea, while the basilar membrane supports hair cells and moves in response to fluid waves.
Forgetting the role of the auditory nerve
Why it happens: The final step in the transmission process can be overlooked.
Fix: Always mention that electrical signals generated by hair cells are sent to the brain via the auditory nerve for interpretation as sound.
Where the marks go
The question types you’ll meet on this topic and the marks each one carries — so you know what to expect and where to focus.
| Question type | What you’re asked to do | Marks |
|---|---|---|
| Label Ear Diagram | Identify and correctly label the anatomical parts of the ear on a diagram. | 5 |
| Sound Transmission Pathway | Describe the step-by-step journey of sound from the outer ear to the brain. | 6 |
| Describe Structure Function | State what each named part of the ear does in hearing. | 8 |
| Explain Sound Transmission | Explain how the ossicles function in transmitting and amplifying sound vibrations through the ear. | 4 |
| Total across these question types | 23 | |
Question types and mark tariffs are Gradora’s guidance based on how this topic is typically examined — not the board’s official paper structure.