Ear – The Organ of Hearing & Balance

Ear is a complex structure. It is divided into 3 main parts.

Outer Ear

It includes the pinna and ear canal.

Middle Ear

It is air filled cavity behind the tympanic membrane. It connected to the nasopharynx by Eustachian tube. Ossicular Chain (Malleus, Incus and Stapes) form a bridge between tympanic membrane to cochlea.

Inner Ear

It contains Cochlea and Vestibular system. Hearing Nerve (VIII Cranial Nerve) connects inner ear to central auditory system.

How We Hear?

  • Acoustic sounds enter the ear canal and set tympanic membrane into vibration.
  • These vibration reaches to Ossicular chain which is connected to inner ear cochlea.
  • Then the inner ear cochlear fluid carries the vibrations to thousands of tiny outer and inner hair cells.
  • The movement of the cochlear fluid causes the tiny inner and outer hair cells to carry signals to the hearing nerve that is connected to the brain, which turns it into a sound that we recognize and understand.