INTRODUCTION

INTRODUCTION

How do you come to know that a 'period’ is over in your school? 

You come to know easily that someone is at your door when he knocks or you hear the sound of the doorbell. Most of the time you can make out that someone is approaching you by just hearing the footsteps.

You might have played a game called hide and seek. In this game, a person is blind-folded and has to catch the remaining players. How is the blindfolded person able to guess which player is closest to her?

Sound plays an important role in our lives. It helps us to communicate with one another. We hear a variety of sounds in our surroundings.

Make a list of sounds you hear in your surroundings.

In the music room of your school, you hear the sounds produced by musical instruments like flute, tabla, harmonium, etc. (Fig 13.1).

Figure 13.1: Some musical instruments

How is the sound produced? How does it travel from one place to another? How do we hear the sound? Why are some sounds louder than others? We shall discuss such questions in this chapter.

Source: This topic is taken from NCERT TEXTBOOK