Diagram of Ear- Structure, Function and Parts of Human Ear

Diagram of Ear: Structure, Function, Parts

Edited By Irshad Anwar | Updated on Jul 02, 2025 06:48 PM IST

The ear diagram is important to understand the structure and function of the auditory system that helps us perceive sound and maintain our balance. There are three main parts-the outer, middle, and inner ear- and all function together in terms of processing sound waves. This topic is given in Class 11 as a part of the chapter Neural Control and Coordination in Biology

Diagram of Ear: Structure, Function, Parts

The Human Ear

The human ear is an organ that helps in hearing sounds and maintaining one's balance. Its main parts are the outer ear, which collects sounds; the middle ear, which amplifies sound; and the inner ear, which translates the sounds into signals to be understood by the brain. The inner ear also contains a system for helping us maintain our balance. All these work collectively to make us hear and stay steady on our feet.

Human Ear Diagram

The labelled Diagram of the Human Ear is given below:

Human Ear

Description of Ear Diagram

The pinna is the external part and collects the sound waves.
The ear canal goes from the pinna to the eardrum.
At the end of the ear canal, a thin membrane is represented as the eardrum.
Represented behind the eardrum ossicles, which are malleus, incus, and stapes forming a chain in the middle ear.
The cochlea is represented by a spiral structure in the inner ear.
Semicircular canals as loop-like structures that lie beside the cochlea show the auditory nerve coming out of the cochlea indicating the auditory signals have passed through it to the brain.

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Parts of the Ear

The structure of the human ear is explained in detail below:

External Ear

The external ear collects the sound waves and leads them into the ear canal.

Pinna (Auricle)

That projecting visible part of the ear which aids in collecting sound waves.

Ear Canal (External Auditory Meatus)

The tube that carries the sound waves to the eardrum.

Middle Ear

The middle ear amplifies sound waves and conducts them into the inner ear.

Eardrum (Tympanic Membrane)

A thin membrane that vibrates to the waves of sound.

Ossicles

Three very small bones, malleus, incus, and stapes, which amplify the vibration from the eardrum.

Inner Ear

These waves are then translated by the inner ear into electrical impulses that will then be passed to the auditory nerve and are also responsible for balance.

Cochlea

Spirally-ended organs with hair cells that convert sound into nerve impulses.

Semicircular Canals

Structures maintaining balance and spatial orientation.

Also Read:

Mechanism of Hearing	Receptors
Disorders of Eye and Ear	Structure of the Human Eye
Mechanism of Vision	Neuron

Frequently Asked Questions (FAQs)

1. What are the major parts of the external ear?

The pinna and ear canal.

2. How do the ossicles function in the middle ear?

The ossicles increase the pressure of the sound vibrations and then send them into the inner ear.

3. What is the function of the cochlea in hearing?

The cochlea converts the sound vibrations into electrical signals.

4. How are semicircular canals beneficial to balance?

The semicircular canals sense head movements and then maintain the balance.

5. And how about the eardrum?

The eardrums vibrate upon the impulse of the sound waves and transfer these impulses to vibrate the ossicles.

6. What is the difference between conductive and sensorineural hearing loss?

Conductive hearing loss occurs when there's a problem in the outer or middle ear that prevents sound from reaching the inner ear effectively. This can be due to issues like ear wax blockage or damaged ossicles. Sensorineural hearing loss, on the other hand, results from damage to the inner ear (cochlea) or the auditory nerve, affecting the conversion of sound waves into electrical signals or their transmission to the brain.

7. How does the ear contribute to our sense of balance?

The ear contributes to balance through the vestibular system in the inner ear. This system includes the semicircular canals and the otolith organs (utricle and saccule). The semicircular canals detect rotational movements, while the otolith organs sense linear acceleration and head position relative to gravity. Together, they provide information to the brain about the body's position and movement in space.

8. What is the cochlea, and how does it work?

The cochlea is a snail-shaped structure in the inner ear responsible for converting mechanical vibrations into electrical signals. It contains fluid and thousands of tiny hair cells. As sound vibrations enter the cochlea, they cause the fluid to move, bending the hair cells. This bending triggers the hair cells to release neurotransmitters, creating electrical signals that are sent to the brain via the auditory nerve.

9. How do the semicircular canals work?

The semicircular canals are three fluid-filled tubes in the inner ear, arranged at right angles to each other. When the head rotates, the fluid in these canals moves, stimulating hair cells. Each canal detects rotation in a different plane (horizontal, vertical, and diagonal), allowing the brain to determine the direction and speed of head movement, which is crucial for maintaining balance.

10. What is the function of the round window?

The round window is a membrane-covered opening between the middle ear and the inner ear. Its primary function is to act as a pressure release valve for the cochlea. When sound vibrations cause the stapes to push on the oval window, the round window bulges outward, allowing the incompressible fluid in the cochlea to move. This movement is crucial for the proper functioning of the cochlea in sound transduction.

11. What are the three main parts of the ear?

The three main parts of the ear are:

12. How does the shape of the outer ear contribute to hearing?

The shape of the outer ear, particularly the pinna (the visible part), helps to collect and funnel sound waves into the ear canal. Its unique folds and ridges also assist in determining the direction of sound, enhancing our ability to localize sound sources.

13. What is the tympanic membrane, and what is its role?

The tympanic membrane, commonly known as the eardrum, is a thin, cone-shaped membrane that separates the outer ear from the middle ear. Its role is to vibrate in response to sound waves, converting sound energy into mechanical energy that can be transmitted to the ossicles in the middle ear.

14. What are the ossicles, and why are they important?

The ossicles are three tiny bones in the middle ear: the malleus (hammer), incus (anvil), and stapes (stirrup). They are important because they amplify and transmit sound vibrations from the eardrum to the inner ear, effectively bridging the air-filled middle ear with the fluid-filled inner ear.

15. How does sound travel through the ear?

Sound travels through the ear in a specific sequence: First, sound waves enter the outer ear and travel down the ear canal. They then cause the eardrum to vibrate, which in turn moves the three tiny bones in the middle ear (ossicles). These bones amplify the vibrations and transfer them to the cochlea in the inner ear, where they are converted into electrical signals sent to the brain.

16. What is the main function of the ear?

The main function of the ear is to detect and process sound waves, converting them into electrical signals that the brain can interpret. Additionally, the ear plays a crucial role in maintaining balance and spatial orientation.

17. How do ear infections affect hearing?

Ear infections can affect hearing in several ways:

18. What is otoacoustic emission and how is it used in hearing tests?

Otoacoustic emissions (OAEs) are low-level sounds produced by the cochlea, specifically by the outer hair cells:

19. How does the brain determine the direction of a sound?

The brain determines the direction of a sound through several cues:

20. How does age-related hearing loss (presbycusis) occur?

Age-related hearing loss, or presbycusis, typically occurs gradually over time due to several factors:

21. How does the auditory cortex process sound information?

The auditory cortex, located in the temporal lobe of the brain, is responsible for processing and interpreting sound information. It receives signals from the auditory nerve via several intermediate structures. The auditory cortex is organized tonotopically, meaning different areas respond to different frequencies. It processes various aspects of sound, including pitch, volume, location, and complex patterns like speech and music. The auditory cortex also integrates auditory information with other sensory inputs and cognitive processes.

22. How does the vestibulo-ocular reflex work?

The vestibulo-ocular reflex (VOR) is a reflex eye movement that stabilizes images on the retina during head movement:

23. What is the difference between absolute and relative pitch perception?

Absolute pitch (or perfect pitch) is the ability to identify or produce a specific musical note without any reference tone. It's a rare ability that is thought to be influenced by both genetic and environmental factors. Relative pitch, on the other hand, is the ability to identify or produce a musical note in relation to another note. Most people, including trained musicians, have relative pitch. The difference lies in how the brain processes and remembers pitch information, with absolute pitch involving more direct mapping of sound frequencies to pitch labels in long-term memory.

24. How does the efferent auditory system work?

The efferent auditory system is a network of nerve fibers that carry signals from the brain back to the cochlea:

25. What is the role of hair cell polarization in sound transduction?

Hair cell polarization is crucial in the process of sound transduction:

26. How does the Eustachian tube maintain pressure in the ear?

The Eustachian tube connects the middle ear to the back of the throat. It helps equalize air pressure between the middle ear and the outside environment by opening briefly when we swallow or yawn. This pressure equalization is crucial for the proper functioning of the eardrum and prevents discomfort during altitude changes.

27. What is the role of hair cells in hearing?

Hair cells in the cochlea are crucial for hearing. They convert mechanical vibrations into electrical signals. When sound waves cause the fluid in the cochlea to move, it bends these hair cells. This bending opens ion channels, leading to the release of neurotransmitters and the generation of electrical signals that are sent to the brain, where they are interpreted as sound.

28. How does the brain interpret pitch?

The brain interprets pitch based on which hair cells in the cochlea are stimulated. The cochlea is tonotopically organized, meaning different frequencies stimulate hair cells at different locations along its length. High-frequency sounds activate hair cells near the base of the cochlea, while low-frequency sounds activate those near the apex. The brain interprets these patterns of activation as different pitches.

29. How does loud noise damage hearing?

Loud noise can damage hearing by overstimulating the hair cells in the cochlea. Prolonged exposure to intense sound can cause these cells to become fatigued and eventually die. Unlike many other cells in the body, hair cells in humans do not regenerate once damaged or destroyed, leading to permanent hearing loss. This is why protecting ears from loud noises is crucial for maintaining long-term hearing health.

30. What is the role of cerumen (ear wax)?

Cerumen, commonly known as ear wax, plays several important roles:

31. How do otoliths contribute to balance?

Otoliths are tiny calcium carbonate crystals found in the utricle and saccule of the inner ear. They sit on top of hair cells and move in response to gravity and linear acceleration. When the head tilts or moves in a straight line, the otoliths shift, bending the hair cells beneath them. This movement is detected and sent to the brain, providing information about the head's position relative to gravity and linear motion, which is crucial for maintaining balance.

32. What is the function of the oval window?

The oval window is a membrane-covered opening between the middle and inner ear. Its primary function is to transmit sound vibrations from the middle ear to the fluid-filled inner ear. The footplate of the stapes (the last of the three middle ear bones) fits into the oval window. When the stapes vibrates, it causes the oval window to move, which in turn creates waves in the fluid of the cochlea, initiating the process of sound transduction.

33. What is the function of the vestibular nerve?

The vestibular nerve, also known as the balance nerve, carries information from the vestibular system in the inner ear to the brain. It transmits signals about head position, movement, and spatial orientation from the semicircular canals and otolith organs. This information is crucial for maintaining balance, coordinating eye movements, and spatial awareness.

34. What is the role of stereocilia in hearing?

Stereocilia are the hair-like projections on top of the hair cells in the cochlea. They play a crucial role in converting mechanical energy (sound vibrations) into electrical signals. When sound waves cause fluid movement in the cochlea, the stereocilia bend. This bending opens ion channels, allowing potassium and calcium ions to enter the hair cell. This influx of ions causes the release of neurotransmitters, generating an electrical signal that is sent to the brain via the auditory nerve.

35. What is the function of the organ of Corti?

The organ of Corti is the primary organ for hearing in the inner ear, located within the cochlea. Its main functions include:

36. What is the role of the stapedius muscle?

The stapedius muscle, the smallest skeletal muscle in the human body, plays a crucial protective role in hearing:

37. How does the brain process binaural beats?

Binaural beats occur when two tones of slightly different frequencies are presented separately to each ear:

38. How does the cochlear amplifier work?

The cochlear amplifier is a mechanism that enhances the sensitivity and frequency selectivity of hearing:

39. What is the function of the helicotrema in the cochlea?

The helicotrema is a small opening at the apex of the cochlea that connects the scala tympani and scala vestibuli: