The document summarizes the working of the human ear. It is divided into three main parts - the outer, middle and inner ear. The outer ear collects sound waves and directs them through the ear canal to the eardrum. In the middle ear, three small bones called the hammer, anvil and stirrup transmit vibrations from the eardrum to the inner ear. The inner ear contains the cochlea, which transforms sound vibrations into nerve signals that are sent to the brain via the auditory nerve.

1. Before presenting my PPT on
the topic “Working of a
Human Ear”, I would like to
thank Anjali Rajpal ma’am for
inspiring me to increase my
knowledge about Science.

2. Definition of
ear: the organ
used by humans
to detect sound.

4. Each part of the ear serves a specific
purpose in the task of detecting and
interpreting sound.

5.  Picture a satellite dish that
collects radio waves.
 The outer ear is similar!
 The curved formation on the
outside ( the pinna) helps
funnel sound down the ear
canal to the eardrum.

6.  The middle
ear transfers
the energy of
a sound wave
by vibrating
the three
bones found
there.

7.  These are
the smallest
bones in
your body!
 Together,
they’re
about the
size of an
orange seed.
Hammer
Anvil
Eardrum Stirrup

8.  When sound waves
reach the middle ear,
they cause the
eardrum to vibrate.
 This vibration then
causes the three
bones to vibrate.
 These vibrations are
transformed into
longitudinal/pressure
waves in the middle
ear.

9. Two main parts:
Cochlea
Auditory Nerve

10.  Coiled like a snail shell
 Contains approximately
300,000 hair cells
 Is filled with fluid,
through which sound
can travel easily.

11.  These tiny
hairs bend
because of
the
vibrations
caused by
the sound
waves.

13.  The tiny hair cells
of the cochlea are
set in motion by
vibrations
 The vibrations
stimulate tiny
nerve cells.
 The nerve cells
then send signals
along the auditory
nerve to the brain.