THE HUMAN EAR
The Ear is the organ of hearing in animals. It receives the vibrations from the surroundings and perceives
them as sound. Ear also performs the function of balancing.
Major Parts of the Ear (related to hearing)
The Ear is divided into 3 parts – External, Middle and Internal Ear
I. External Ear
1. Pinna: It is a funnel shaped organ in the external ear. It collects the sound waves from the
surroundings in order to direct them inside the ear.
2. Ear Canal or Auditory Canal: It is a tube like canal which leads from the pinna to the eardrum. It
directs the sound waves inside the ear.
II. Middle Ear
1. Eardrum or Tympanic Membrane or Tympanum: It is a membranous organ in the external ear
where sound waves hit. The eardrum vibrates due to those vibrations which are transported to the
middle ear.
2. Ear Ossicles: These are three tiny bones present in the ear. They are connected to each other. The
three ear ossicles are
a) Malleus or Hammer
b) Incus or Anvil
c) Stapes or Stirrup
The stapes is the smallest bone in the body. One end of the hammer is connected to the eardrum while
the other end of the stapes is connected to the Oval Window.
The Ear Ossicles amplify the sound waves received from the eardrum and transmit them to the inner ear.
3. Oval Window: It is also called Fenestra Ovalis. It is connected to one end of the stapes. It receives the
vibrations and transmits to the inner ear.
III. Inner Ear
1. Cochlea: It is a two and a half spiral shaped structure resembling a snail shell. It consists of three
canals inside filled with fluid. It also contains hair like receptor cells. The vibrations are transmitted
inside the cochlear fluid which agitates the hair receptor cells. These receptor cells convert the vibrations
into impulses.
2. Auditory Nerve: It picks up the impulses generated in the cochlea and transmits them to the brain.
Path of Sound in Human Ear
PINNA AUDITORY EARDRUM HAMMER ANVIL
CANAL
AUDITORY COCHLEA (Hair OVAL STIRRUP
NERVE receptors) WINDOW
