​FLOW OF THE LESSON

​1) Introduction

2) Production of Sound

3) Sound produced by humans

4) Propagation of sound

5) Human Ear

6) Characteristics of Sound ​

7) Audible And Inaudible

8) Noise, Music and Noise Pollution ​

​INTRODUCTION

Subject | Subject

​HOW WE CAN HEAR THE BELL WHEN THE LESSON IS OVER?

​PRODUCTION OF SOUND

• ​Sound is produced by vibration of an object

• ​Vibration is rapid to and fro motion of an object and it is also referred as 'oscillation'.

​sound produced by humans

• ​In humans, sound is produced by the voice box or the larynx. it is situated at the upper end of wind pipe

• Two vocal cords are stretched across the voice box .​

• Muscles attached ​to the vocal cord can make the cord loose or tight and thin.​

​propagation of sound

• ​A medium is required for sound movement.

• A medium is a matter through which sound is transmitted is called a medium .​ this can be liquid , solid and gas.

​human ear