In a loud - speaker , sound is produced by a diaphragm on supplying electrical energy . Explain what type of motion the diaphragm exhibits while producing the sound ? How is sound produced in a loud speaker ?

Explanation

A diaphragm exhibits vibratory motion to produce sound . As the diaphragm moves forward , it compresses the air in front of it , hence , density of air increases at that place . This part of air causes next layer of air to compress and the wave travels in the air with certain speed creating compressions .
When a membrane moves backwards , it drags back the air layer near it decreasing the density of air in the adjacent layer. Thus , the wave advances in the air in the form of rarefaction .