Learn Class 8 Science - Sound

We all know that sound is one thing that we listen to everywhere in our daily life.

Meaning of Sound

The term sound refers to the vibrations that travel from in the air. Or it chooses any other medium to travel.

• Medium only helps to travel.
• And as a result, it reaches the ear.

Types of Sound

Audible Sound:

• Frequency lies between 20-20000 HZ.
• Readily available and heard by the human ear.

Inaudible Sound:

• Frequency below 20 HZ and above 20000 HZ.
• Difficulty in hearing by the human ear.

Hearing process:

See the sound hearing process below:

• Sounds get produced with waves.
• Waves reach the air.
• Convert them into 'messages' or 'electrical signals.'

Parts:

Three main parts of the ear are as below:

Pinna (outer-ear):

• It catches the sound waves.
• And do the forwarding process, i.e., to (middle-ear).

Middle ear:

• Convert sound waves to 'vibrations.'
• Use 'Eardrum.'
• And send them to the cochlea.

Cochlea (inner-ear):

• It receives vibrations.
• Tiny hairs: do the conversion of vibrations to signals. I.e., to the brain.
• The brain gets the signals and interprets them to sound.

Pitch:

• Pitch helps in determining the sound.
• Pitch depends on the frequency of sound.

Learning Videos for 8th Grade Science - Sound