Sound is a very important part of our life.
We wake up in the morning by hearing alarms, or the chirping of birds.
Sound helps us to communicate with another person.
We talk and express ourselves by using sound.
We hear and listen to others with the help of sound.
Let's discuss some sounds in our daily life.
A dog's bark lets us know that someone is coming.
A fire alarm warns us of a fire.
All these things show how important sound is in our daily life.
Have you ever thought about how are these sounds produced?
Let us understand what is sound, and how is it produced, by taking an example of a guitar.
What happens when we pluck the strings of a guitar?
We hear sound.
What is producing this sound? Let us try to find out.
When a string of a guitar is plucked, it moves from one side to another in a back and forth motion or you can say it vibrates.
When the string moves to any one side, the surrounding air particles also shift to one side. When the string moves to the other side, the surrounding particles shift in the same way.
The continuously moving strings of a guitar shift the air particles in their respective directions. So, the vibrations of guitar strings set the surrounding air particles into vibrations, and this produces sound.
As the vibrations of the guitar strings come to a stop, the surrounding air particles also stop vibrating and we cannot hear any more sound being produced.
Now, let us see what happens when we hit the cover of a drum, called the membrane, with a drumstick.
The cover of the drum vibrates.
The surrounding air particles are also set into vibration, and as a result, sound is produced.
Let us see what happens when we blow air inside a flute or a trumpet. Here again, air particles vibrate and sound is produced.
Now that you have understood what is sound and how it is produced, let us now talk about different sounds and some properties of sound.
First, let us compare the sound of a whistle with that of a drum.
You will notice that blowing a whistle produces a high sound, while a drum produces a low sound.
Do you know how we label such high and low sounds?
We say high sounds are high pitch sounds, while low sounds are low pitch sounds.
So, blowing a whistle produces a high pitch sound while hitting a drum produces a low pitch sound.
Now compare the sounds produced by a violin and a human heartbeat.
High pitch sounds
Low pitch sounds
You will realize that a violin produces a high pitch sound, while human heartbeat has a low pitch sound.
In a similar way, chirping of birds is a high pitch sound, while a lion's roar is a low pitch sound.
Let us now compare the sound produced when a person whispers into someone's ears and the sound produced when the same person shouts for a friend across the playground.
You will notice that whispering makes a soft sound but shouting for a friend across a playground makes a loud sound.
And a loud or soft sound is identified by its volume, another property of sound.
Loud sound has a high volume while soft sound has a low volume.
Banging of a hammer and a car's horn are examples of loud sounds while playing of a piano and sound of blowing wind are examples of soft sounds.
Sound is very important in our daily life. It helps us in communicating with people or warning someone.
Sound is a form of energy which is produced by vibrating bodies.
The pitch of a sound tells us how high or low a sound is.The volume of a sound tells us how loud or soft a sound is.
A. Identify Different Sounds
B. Identify high and low pitch sound
C. Make your own Musical Instrument