science presentation of sound ch 13

1.Topics to be covered :

Sound

Production of sound and How sound travels

Sound produced by humans

Sound produced by musical instruments

How humans hear sound

Amplitude ,time period and frequency of vibration

Loudness and Pitch

Amplitude , time period and frequency of a vibration

Audible and Inaudible sounds

Noise or Music

Noise pollution.

2.Sound:

Vibrations that travel through the air

or another medium and can be heard

when they reach a person's or animal's

ear are called Sound.

3.Production of sound and how sound

travels :

Sound is produced by a vibrating body.

The to and fro motion of an object is called

vibration.

When a object stops vibrating ,it does not

produce any sound.

4.How sound is produced in humans:

5.Sound produced by musical

instruments:

In musical instruments sound is produced with

the help of vibrating parts.

In different musical instruments different

parts vibrate to produce sound

Eg. In tabla stretched membrane vibrates to

produce sound ,in flute air column vibrates to

produce sound ,in sitar strings vibrate to

produce sound.

6.How humans hear sound:

Human and every animal hears sounds through their ears.

Sound Waves enter the ear canal and cause the eardrum to vibrate. Vibrations pass through three connected bones in the middle ear. This motion Sets Fluid Moving in the inner ear.

7.Amplitude ,time period and Frequency

of a vibration:

Vibration is the to and fro motion of a object . It is also called

oscillatory motion of a object.

8.Loudness and Pitch:

9.Audible and Inaudible sounds:

10.Noise or Musical sound:

11.Noise Pollution

12.Some causes due to which noise

pollution is caused: