Question

what is sound? why it is neccesary in our life

Answer 1

- Anything that can be heard is sound. It is a continuous disturbance that can produce sensation in human ear.
- We hear numerous sounds every day. Sounds tell us what is going on in our surroundings. They are one of the five senses- hearing sense. We usually use sound for signalling, like shouting or calling somebody. Sound is also important for communication. When somebody talks- that is produce sound - we are able to communicate.

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Answer 2

Sound is the form of energy that we hear and listen through our ears. SOund causes our ear drum to vibrate and cause hearing stimulus in our body. 

Sound actually is generated by changes in pressure in air.  Sound travels in a medium and cannot travel in vacuum. 

Sound is necessary in our life for us to hear the various beautiful, sweet, rhythmic sounds in the nature.  It is necessary for us to communicate with each other using a language.