Sound (part -3) class 8

                                                                              SOUND

Q.6. Draw a well labeled diagram of human ear and explain its functioning?

Ans. A human ear is divided into 3 parts:

1. Outer Ear: It is the only part of the ear that is visible to us. It consists of Pinna, Ear Canal and Ear Drum. The Pinna collects the sound waves and directs them to the ear canal. At the end of ear canal, there is ear drum which is slightly stretched membrane. When the vibrations strike the ear drum, it starts vibrating and transmits the sound to the middle ear.

2. Middle Ear: The middle ear is a cavity with three tiny important ear bones. These bones are Malleus (Hammer), Incus (Anvil) and Stapes (stirrup). When the ear drum vibrates, these bones also vibrate and transmit the vibration to inner ear.

3. Inner Ear: This part consist of Cochlea which is a long coiled tube. This contains a fluid that contains nerve cells which are sensitive to sound. These cells transform the vibration into electrical impulses, which are then transferred to brain through Auditory Nerve and brain interprets the message.

 Human ear | Class 9, Sound

Q.7. Why a hard and sharp object should not be inserted into our ears?

Ans. We should not put anything (like pencil, pen or pin, etc.) inside our ears because they can tear the ear-drum (a thin, elastic and circular membrane). The tearing of ear-drum can make a person deaf.


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