Production of Sound

Introduction

Sound is produced when an object vibrates. In our daily life, we hear many sounds such as voices, music, bells, drums, vehicle horns, and birds chirping. In all these cases, some object or part of an object vibrates and produces sound.

For example, when we pluck a stretched rubber band, beat a drum, strike a metal plate, or speak, vibrations are produced. These vibrations create sound.

How is Sound Produced?

Sound is produced by vibrating objects.

Vibrating object → Sound

When an object moves to and fro rapidly about its mean position, it is said to vibrate. These vibrations disturb the surrounding air and produce sound waves.

Vibration

Vibration is the periodic to and fro motion of an object about its mean position.

For example, when a stretched rubber band is plucked, it moves rapidly up and down. This rapid motion is called vibration. As long as the rubber band vibrates, sound is produced. When the vibration stops, the sound also stops.

Activity: Sound from a Rubber Band

Take a cardboard box with one side open and stretch a rubber band across it. Now pluck the rubber band with your finger.

You will hear a sound. If you observe carefully, you will notice that the rubber band is vibrating. When the rubber band stops vibrating, the sound also stops.

Figure

Explanation

In the above figure, a rubber band is stretched across a cardboard box. When the rubber band is plucked, it starts vibrating. These vibrations disturb the surrounding air and produce sound.

The sound continues only while the rubber band is vibrating. When the rubber band comes to rest, no sound is produced.

This shows that sound is produced due to vibrations.

Source of Sound

The object that produces sound is called the source of sound.

For example:

In a ringing bell, the bell is the source of sound.
In a drum, the stretched membrane is the source of sound.
In a flute, the vibrating air column is the source of sound.
In a guitar, the vibrating strings are the source of sound.
In humans, vibrating vocal cords produce sound.

Different Ways of Producing Sound

Sound can be produced in many ways. In each case, vibration is involved.

1. By Plucking

When a stretched string is plucked, it vibrates and produces sound.

Example: Guitar
Example: Sitar
Example: Rubber band

2. By Striking

When an object is struck, it starts vibrating and produces sound.

Example: Bell
Example: Metal plate
Example: Tuning fork

3. By Beating

When the membrane of a drum is beaten, it vibrates and produces sound.

Example: Drum
Example: Tabla
Example: Dholak

4. By Blowing Air

When air is blown into some musical instruments, the air column inside them vibrates and produces sound.

Example: Flute
Example: Whistle
Example: Shehnai

5. By Rubbing

Some animals produce sound by rubbing body parts. Some musical instruments also produce sound when their parts are rubbed.

Example: Cricket rubbing its wings or legs
Example: Violin string rubbed with a bow

Sound in Musical Instruments

Musical instruments produce sound because some part of the instrument vibrates.

Musical Instrument	Vibrating Part
Guitar	Strings
Tabla	Stretched membrane
Flute	Air column
Bell	Metal body
Drum	Stretched membrane

Examples from Daily Life

When we clap, our hands strike each other and produce sound.
When a bell rings, its metal body vibrates and produces sound.
When we speak, our vocal cords vibrate and produce sound.
When a drum is beaten, its stretched membrane vibrates and produces sound.
When a guitar string is plucked, it vibrates and produces sound.
When air is blown into a flute, the air column vibrates and produces sound.

Important Points

Sound is produced by vibrating objects.
Vibration is the periodic to and fro motion of an object.
When vibration stops, sound also stops.
The object that produces sound is called the source of sound.
Sound can be produced by plucking, striking, beating, blowing, or rubbing.
In musical instruments, sound is produced by vibrating strings, membranes, air columns, or metal parts.
In humans, sound is produced by the vibration of vocal cords.
Every sound has a vibrating source.

Conclusion

Sound is produced when an object vibrates. The vibrating object disturbs the surrounding medium and produces sound waves. Different objects produce sound in different ways, such as by plucking, striking, beating, blowing, or rubbing. However, the basic cause of sound production is always vibration. Therefore, vibration is essential for the production of sound.