Mechanism of Hearing: How does ear convert sound waves into neural impulses, which are sensed and processed by the brain enabling us to recognise a sound ?

Mechanism of Hearing

• The sound waves travel to the ear canal (external auditory canal in the figure). This is a tube-shaped opening in the ear.
• At the end of the ear canal, the sound waves hit the eardrum (tympanic membrane). This is a thin membrane that vibrates like the head of a drum when sound waves hit it.
• The vibrations pass from the eardrum to the hammer (malleus). This is the first of three tiny bones that pass vibrations through the ear.
• The hammer passes the vibrations to the anvil (incus), the second tiny bone that passes vibrations through the ear.
• The anvil passes the vibrations to the stirrup (stapes), the third tiny bone that passes vibrations through the ear.
• From the stirrup, the vibrations pass to the oval window. This is another membrane like the eardrum.
• The oval window passes the vibrations to the cochlea. The cochlea is filled with liquid that moves when the vibrations pass through, like the waves in water when you drop a pebble into a pond. Tiny hair cells line the cochlea and bend when the liquid moves. When the hair cells bend, they release neurotransmitters.
• The neurotransmitters trigger nerve impulses that travel to the brain through the auditory nerve (cochlear nerve). The brain reads the sound and “tells” you what you are hearing.

Follow on Facebook

By Team Learning Mantras