Summary
Sound vibrations pass through the ossicles to the cochlea, where hair cells produce nerve impulses.
In depth
Sound waves vibrate the eardrum, ossicles (malleus, incus, stapes) amplify, oval window moves cochlear fluid, and hair cells on the basilar membrane convert movement to signals. Different frequencies activate different positions. The vestibular system handles balance.
The Eustachian tube equalises pressure. Cochlear hair cells have stereocilia that open channels when bent. Frequency is mapped along the cochlea (tonotopy).
Remember: balance depends on semicircular canals and otoliths.
Sound is funnelled by the pinna and canal to the eardrum; the ossicles amplify pressure about 20-fold (impedance matching), and the stapes drives the oval window. In the cochlea, the basilar membrane is tuned: high frequencies at the base, low at the apex (tonotopy). Hair cells convert motion to electrical signals by deflection of stereocilia, opening mechanically gated channels. Outer hair cells amplify, and inner hair cells (about 3500) signal to the auditory nerve.
Humans hear 20 Hz to 20 kHz, with greatest sensitivity at 2 to 5 kHz. The vestibular system (semicircular canals and otoliths) senses rotation and gravity. Hearing loss may be conductive or sensorineural; hair cells do not regenerate in mammals, so loud noise causes permanent damage. Cochlear implants stimulate the nerve directly. Tinnitus is ringing in the ears.
Key idea: the ear acts as a mechanical frequency analyser before nerve signals are formed.
Frequently asked questions
What is Ear and Hearing?
Sound vibrations pass through the ossicles to the cochlea, where hair cells produce nerve impulses.
Which area of biology covers Ear and Hearing, and how advanced is it?
Ear and Hearing is one of the 54 topics in Neuroscience. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Sensory Receptors, Action Potential, Depolarisation and Repolarisation.
Can you give an example of Ear and Hearing?
Loud noise damages hair cells permanently.
What should I learn before Ear and Hearing?
Ear and Hearing is a Beginner topic, so no earlier topic is required. Other Beginner topics in Neuroscience that pair well with it include Nervous System, Neuron, Central and Peripheral Nervous Systems.
What topics are related to Ear and Hearing?
The closest topics to Ear and Hearing are Sensory Receptors, Action Potential, Depolarisation and Repolarisation, Neuron. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Ear and Hearing?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Ear and Hearing. To practise the whole of Neuroscience, use the Neuroscience quiz.
How is Ear and Hearing different from Sensory Receptors?
Ear and Hearing: Sound vibrations pass through the ossicles to the cochlea, where hair cells produce nerve impulses. Sensory Receptors: Mechanoreceptors, thermoreceptors, chemoreceptors and photoreceptors transduce stimuli into signals. Read both side by side and note what each one explains.
How should I study Ear and Hearing step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Sensory Receptors and explain the difference aloud. Finally, take the Neuroscience quiz and come back to this page for any question you miss.