How do we hear simple vibrations of air molecules as sound with different frequences and tunes? Let’s understand it together!
Let’s have a look to the parts of human ear to learn it better.
Our ear is divided into three parts. These work together to hear sound.
- Outer ear ( includes Pinna and ear cannel )
- Middle ear ( including ear drum and Ossicles)
- Inner ear ( including Cochlea)
OUTER EAR
- The shape of outer ear is funnel like.
- It gathers sound from the environment.
- Then, the sound travels down through ear canal. At the end of it a thin, elastic and circular membrane called a eardrum, stretched tightly.
MIDDLE EAR
• The sound vibrates the eardrum that in turn vibrates three soft bones (together called ossicles) attached to it.
• These ossicles amplify (increases) the vibrations as the rest of the ear is filled with fluid, so more pressure is needed to vibrate it.
• And then the vibrations are passed to the inner ear through middle ear bones or ossicles.
OSSCICLES
Three soft bones in our ear have their own fancy names:- First one is malleus, second is Incus and last is Stapes.
common names:- hammer, anvil and stepes
Stepes is the smallest bone in human body.
How the ossicles amplify the vibrations?
- This happens due to the structure of ossicles.
- The area of ear drum is much more larger then of stapes.
- So, the same amount of force when applied on stapes (much more smaller area than eardrum), then the pressure increases. As pressure–> Force/Area.
INNER EAR
- The shape of the inner ear is coiled and snail like. It is also termed as cochlea that is filled with fluid. The hair cells in it convert vibrations into electrical signals.
- Which are then transferred to the brain through auditory nerve.
- The brain interprets these electrical signals as sound and we can enjoy music!
Unified Learners 