### Theory:

Sound is a form of energy which is produced when air molecules vibrate in a particular pattern called waves. Hence, sound travels in the form of a wave.
Sound travels in the form of wave

A sound is always produced by a vibrating body. Sound cannot be produced without any vibration. The SI unit for expressing the loudness of a sound is $$decibel$$ ($$dB$$) .

Sound travels in the form of wave

What is vibration ?
When a body moves to and fro, or up and down , about a fixed position, it is said to be in oscillatory motion. A body exhibiting a rapid oscillatory motion is said to be in vibration.
Every sound we hear in our daily life is different from one another because the vibrations vary from one to another. In our lives, sound plays a crucial role. It facilitates communication between us. In our surroundings, we hear a wide range of sounds. Here we can find different sounds produced by various vibrating body.

 Scribbling of pen Sound of a waterfall Sound of a drum

How do humans produce sound?
Humans possess the ability to produce sounds that helps us to communicate with each other.

But, how this sound is produced?

Human beings generate sound from an organ called the larynx or voice box present in the throat. The larynx is found at the upper end of the trachea (windpipe).

There are two vocal cords in the larynx, with a narrow slit between them. This narrow slit allows the passage of air between the vocal cords. When we talk, air from our lungs is pushed up the windpipe towards the larynx. As this air passes through the narrow slit between the vocal cords, sound is produced.

Anterior and posterior view of larynx
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