Question

Define sound?
Sound means nouice

Answer 1

Simple definition of sound is; Anything that can be heard. 
Scintific one; Vibrations that travel through any medium , particulalrly air, and are heard when they reach human ear .(or any other organ, through which the organism can hear.)
NO, sound is not noise. 
Noise is any unpleasent, unwanted, irritating sound.
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Answer 2

Sound is a form of energy like electricity or light.It is made when air molecules vibrate and move in a pattern called waves.