BiologyICSE Class 10 · Nervous System and Sense Organs

The Human Ear: Structure, Hearing and Balance (ICSE Class 10 Biology)

Updated 16 October 2026 · Fact-checked

The ear has three parts. The external ear (pinna, auditory canal, eardrum) collects sound. The middle ear's ossicles, malleus, incus and stapes, pass vibrations to the oval window, and the Eustachian tube equalises pressure. In the inner ear, the cochlea's organ of Corti detects sound, while the vestibule and semicircular canals maintain balance.

Understand The Human Ear: Hearing and Balance

Two jobs, one organ. The ear does two things: hearing and keeping the body's balance (equilibrium).

External ear.

Pinna: the flap of skin and cartilage that collects sound waves and directs them inwards.
External auditory canal: tube with hairs and wax glands; wax traps dust and germs.
Tympanum (eardrum): thin membrane at the inner end of the canal; vibrates when sound strikes it.

Middle ear (an air-filled cavity).

Three ear ossicles, in order: malleus (hammer, attached to the eardrum) → incus (anvil) → stapes (stirrup, fitting into the oval window). They pass vibrations inward and amplify them. The stapes is the smallest bone in the body.
Eustachian tube: connects the middle ear to the throat (pharynx); it equalises air pressure on both sides of the eardrum. Germs from a throat infection can travel up it and infect the middle ear, causing earache.

Inner ear (membranous labyrinth, filled with fluid).

Part	Function
Cochlea (spirally coiled) with the organ of Corti	hearing: sensory hair cells turn fluid vibrations into nerve impulses
Vestibule: utriculus and sacculus	static balance: position of the head with respect to gravity, when still or tilted
Three semicircular canals with swellings, the ampullae	dynamic balance: detect rotation and movement of the head

The canals lie in three planes at right angles, so movement in any direction is detected. Signals for hearing go by the auditory nerve to the cerebrum; balance signals reach the cerebellum, which adjusts muscles to keep posture.

Course of perception of sound.
Sound waves → pinna → external auditory canal → eardrum vibrates → malleus → incus → stapes → oval window → fluid in the cochlea vibrates → hair cells of the organ of Corti stimulated → impulses in the auditory nerve → hearing centre of the cerebrum.

Why spinning makes you dizzy. Fluid in the semicircular canals keeps moving for a moment after you stop, so the brain is told you are still turning while your eyes say you are not.

Flow chart: balance. Head moves or tilts → fluid moves in semicircular canals (rotation) or utriculus and sacculus (tilt) → hair cells bend → nerve impulses → cerebellum → muscles adjust → balance kept.

Draw-and-label checklist: L.S. of ear. Pinna and auditory canal on the left; eardrum as a slanting membrane; three ossicles in a chain from eardrum to oval window; Eustachian tube running down from the middle ear; inner ear with three semicircular canals (one ampulla each), vestibule, coiled cochlea and auditory nerve. Labels: pinna, external auditory canal, tympanum, malleus, incus, stapes, oval window, Eustachian tube, semicircular canals, ampulla, utriculus, sacculus, cochlea, auditory nerve.

The Human Ear: Hearing and Balance: key facts

Parts of the ear: External pinna, auditory canal, eardrum
Middle malleus, incus, stapes, Eustachian tube
Inner cochlea, vestibule (utriculus, sacculus), semicircular canals; Ossicles from eardrum to oval window: M-I-S.
Hearing versus balance: Cochlea, organ of Corti hearing
Utriculus and sacculus static balance
Semicircular canals with ampullae dynamic balance; Name the canal, not just the ampulla.
Path of sound: Pinna
Canal
Eardrum
Malleus
Incus
Stapes
Oval window
Cochlea
Auditory nerve
Cerebrum; Ten links, in order.

External	pinna, auditory canal, eardrum
Middle	malleus, incus, stapes, Eustachian tube
Inner	cochlea, vestibule (utriculus, sacculus), semicircular canals

Cochlea, organ of Corti	hearing
Utriculus and sacculus	static balance
Semicircular canals with ampullae	dynamic balance

How to answer The Human Ear: Hearing and Balance questions

ICSE asks you to name the ossicle that touches the inner ear, trace the path of sound, match balance structures to static or dynamic balance in a case, and explain earache after a throat infection.

1For ossicles, remember the order malleus-incus-stapes from the eardrum.
2For balance cases, decide: rotation or movement → semicircular canals; tilt or position at rest → utriculus and sacculus.
3Keep linked parts consistent: if (a) is dynamic balance, its organ is the semicircular canals.
4For throat-ear links, name the Eustachian tube and say germs travel along it.
5Trace sound in full: pinna to cerebrum.

The Human Ear: Hearing and Balance in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Middle-ear infections in young children

Suppose a toddler catches colds and sore throats often, and the doctor warns the parents that middle-ear infections are common at this age.

Explain how a throat infection can reach the middle ear.

Try it first, then show the solutionSolution

The Eustachian tube connects the throat to the middle ear.
Germs from the infected throat travel up the tube.
They infect the middle ear, which becomes inflamed and fills with fluid.
Pressure on the eardrum causes pain.

Answer: Germs spread from the throat to the middle ear through the Eustachian tube.

Memory hook: Throat and ear share a tunnel.

Feeling a lift start

Suppose you stand in a lift with your eyes closed and still feel when it starts moving up and when it tilts slightly as people step in.

Which parts of the inner ear detect these?

Try it first, then show the solutionSolution

A tilt changes the position of the head relative to gravity.
This is static balance, sensed by the utriculus and sacculus in the vestibule.
Sudden starting and stopping are movements, which shift the inner-ear fluid.
Turning movements are sensed by the semicircular canals; signals go to the cerebellum.

Answer: Utriculus and sacculus sense tilt and position; semicircular canals sense turning movements.

Memory hook: Still = sac; spin = semicircular.

Tricks to remember The Human Ear: Hearing and Balance

Short memory aids. Say each one aloud once, then use it on a question the same day.

MIS order
'My Ice-cream Spilled': Malleus, Incus, Stapes from the eardrum inward.
Use it when: Ordering the ossicles.
Cochlea = Coil for Calls
The coiled cochlea hears calls.
Use it when: Hearing organ.
Spin in Semicircles, Stand in Sacs
Rotation: semicircular canals; static position: utriculus and sacculus.
Use it when: Dynamic versus static balance.

The Human Ear: Hearing and Balance: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Positions of the ossicles · 1 mark · MCQBoard level

Which statement about the ear ossicles is correct?
(a) The malleus fits into the oval window. (b) The incus is attached to the eardrum. (c) The stapes is attached to the eardrum. (d) The incus lies between the malleus and the stapes.
(The 2024 paper asked which ossicle passes vibrations to the inner ear.)

Try it first, then show the solutionSolution

The malleus is attached to the eardrum and the stapes fits into the oval window, so (a), (b) and (c) are wrong; the incus is the middle link.

Answer: (d) The incus lies between the malleus and the stapes.

Example 2: Function of the Eustachian tube · 2 marks · Short answerBoard level

State the position and function of the Eustachian tube.

Try it first, then show the solutionSolution

It connects the middle ear to the throat (pharynx) (1 mark).
It equalises air pressure on both sides of the eardrum (1 mark).

Answer: Middle ear to throat; equalises pressure on the eardrum.

Example 3: Putting the path in order · 3 marks · Short answerHarder board level

Arrange these in the order in which sound passes, starting from the pinna: oval window, incus, auditory nerve, eardrum, cochlear fluid, stapes, external auditory canal, malleus, organ of Corti. State which of them converts vibrations into nerve impulses.

Try it first, then show the solutionSolution

Pinna → external auditory canal → eardrum (1 mark).
→ malleus → incus → stapes → oval window → cochlear fluid (1 mark).
→ organ of Corti → auditory nerve; the hair cells of the organ of Corti convert vibrations into nerve impulses (1 mark).

Answer: External auditory canal, eardrum, malleus, incus, stapes, oval window, cochlear fluid, organ of Corti, auditory nerve; the organ of Corti converts vibrations into impulses.

Example 4: Damaged vestibule · 3 marks · Short answerHarder board level

Suppose a person's utriculus and sacculus are damaged but his semicircular canals are normal. (a) Which kind of balance is affected? (b) Would he notice the problem more when tilting his head while standing still with eyes closed, or when spinning round? Explain. (c) To which brain part do these organs send their impulses?

Try it first, then show the solutionSolution

(a) Static balance (1 mark).
(b) When tilting his head while still with eyes closed: the utriculus and sacculus sense head position with respect to gravity, and his eyes cannot help; spinning is sensed by the intact semicircular canals (1 mark).
(c) Cerebellum (1 mark).

Answer: (a) Static balance. (b) Tilting while still with eyes closed, because rotation is still sensed by the semicircular canals. (c) Cerebellum.

Example 5: Dancer's spins · 3 marks · Case-basedHOTS / competency

Suppose a Kathak dancer practises fast spins (chakkars) and, after stopping, the room seems to keep turning. (a) Which structures are involved? (b) Explain why the room seems to turn. (c) How does spotting (fixing the eyes on one point) help her?

Try it first, then show the solutionSolution

(a) The semicircular canals (dynamic balance) (1 mark).
(b) Fluid in the canals keeps moving after she stops, so the brain still receives a 'turning' signal that conflicts with the eyes (1 mark).
(c) Fixing the eyes gives the brain a steady visual reference, reducing the mismatch and dizziness (1 mark).

Answer: (a) Semicircular canals. (b) Moving fluid sends a false turning signal. (c) A fixed visual point steadies the brain's sense of position.

Example 6: Stiff ossicles · 2 marks · Short answerHOTS / competency

Suppose in an elderly person the stapes becomes fixed in the oval window and cannot vibrate. Predict the effect on hearing and balance, with reasons.

Try it first, then show the solutionSolution

Hearing is reduced, because vibrations from the eardrum cannot be passed into the cochlear fluid (1 mark).
Balance is not affected, because the semicircular canals and vestibule do not depend on the ossicles (1 mark).

Answer: Hearing reduced; balance normal.

Where students lose marks in The Human Ear: Hearing and Balance

The slips examiners see most often, and what to write instead.

Mistake: Malleus for stapes
CISCE examiners' comments (2024): for the ossicle that transports vibrations to the inner ear, candidates chose malleus instead of stapes.
Do this: Malleus at the eardrum; stapes at the oval window.
Usually costs: 1 mark.
Mistake: Balance pairs swapped or incomplete
CISCE examiners' comments (2024, 2025): candidates confused the semicircular canals with the utriculus and sacculus, wrote only 'ampulla', and in linked parts paired semicircular canals with static equilibrium or the vestibule with dynamic equilibrium.
Do this: Dynamic = semicircular canals; static = utriculus and sacculus.
Usually costs: 1-2 marks.
Mistake: Earache blamed on 'cold'
CISCE examiners' comments (2025): candidates did not mention the Eustachian tube connecting the throat and middle ear, and did not say pathogens travel from throat to ear.
Do this: Name the Eustachian tube and the spread of germs along it.
Usually costs: 1-2 marks.
Mistake: Auditory canal for pinna
CISCE examiners' comments (2025): in a name-the-structure item, candidates wrote external auditory canal instead of pinna.
Do this: Pinna collects; canal conducts.
Usually costs: 1 mark.

Exam tips

Ossicles: malleus, incus, stapes from the eardrum.
Hearing: cochlea with organ of Corti.
Static: utriculus and sacculus; dynamic: semicircular canals.
Eustachian tube: middle ear to throat, equalises pressure.

Practice questions on The Human Ear: Hearing and Balance

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
The organ of Corti is found in the:
(a) semicircular canals (b) cochlea (c) Eustachian tube (d) vestibule
Hint
Hearing.
Answer
(b) cochlea.
Q2 · 1 mark · Very short answerBoard level
Name the ossicle attached to the eardrum.
Hint
Hammer.
Answer
Malleus.
Q3 · 1 mark · Assertion-reasonHarder board level
Assertion (A): Semicircular canals help in maintaining dynamic balance.
Reason (R): The three canals lie in three planes at right angles and detect rotation of the head.
(a) (A) is true and (R) is false.
(b) (A) is false and (R) is true.
(c) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(d) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
Hint
Three planes.
Answer
(c).
Q4 · 2 marks · Short answerHarder board level
State the functions of (a) the pinna, (b) the ear ossicles.
Hint
Collect; transmit.
Answer
(a) Collects sound waves and directs them into the auditory canal. (b) Transmit and amplify vibrations from the eardrum to the oval window.
Q5 · 2 marks · Short answerHarder board level
Name the nerve that carries impulses from the cochlea and the brain part where sound is interpreted.
Hint
Auditory.
Answer
Auditory nerve; the hearing centre of the cerebrum.
Q6 · 2 marks · Short answerHarder board level
Why can a hard slap over the ear burst the eardrum, and why might it damage hearing?
Hint
Sudden air pressure.
Answer
The slap forces air into the canal suddenly, raising pressure on the thin eardrum, which can tear; a torn eardrum vibrates poorly, so less sound is passed to the ossicles.
Q7 · 2 marks · Short answerHarder board level
Distinguish between static and dynamic balance, naming the structure for each.
Hint
Still or moving.
Answer
Static balance is keeping position with respect to gravity when still or tilted (utriculus and sacculus); dynamic balance is keeping balance during movement or rotation (semicircular canals).
Q8 · 3 marks · Case-basedHOTS / competency
Read and answer.
Suppose a child with a blocked Eustachian tube travels on a plane. During landing she complains of pain and muffled hearing.
(a) What does the Eustachian tube normally do? (1)
(b) Why does the eardrum hurt during landing? (1)
(c) Suggest one action that could help, and why. (1)
Hint
Pressure difference.
Answer
(a) Equalises air pressure on both sides of the eardrum. (b) Outside pressure rises but the middle-ear pressure cannot rise to match, so the eardrum is pushed inward. (c) Swallowing, yawning or chewing, which helps open the tube to let air in.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Which ossicle fits into the oval window?Show answer
Stapes.
2.What connects the middle ear to the throat?Show answer
Eustachian tube.
3.Which part of the inner ear is for hearing?Show answer
Cochlea.
4.What are ampullae?Show answer
Swellings at the base of the semicircular canals with sensory cells.
5.Which part of the brain uses balance information?Show answer
Cerebellum.

The Human Ear: Hearing and Balance: frequently asked questions

Is the vestibule the same as utriculus and sacculus?

The vestibule is the central part of the inner ear containing the utriculus and sacculus.

Do I need the scala vestibuli and scala tympani?

No. Parts and functions at the level on this page are enough.

Why is the Eustachian tube useful when swallowing?

Swallowing opens it briefly, letting air in or out so that pressure on the eardrum stays equal.

Can a person lose balance but hear normally?

Yes. Balance and hearing use different parts of the inner ear.