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10 Types of Microphones

Carbon Microphones
Carbon microphone
Carbon microphone
© Rothrum

The oldest and simplest microphone uses carbon dust. This is the technology used in the first telephones and is still used in some telephones today. The carbon dust has a thin metal or plastic diaphragm on one side. As sound waves hit the diaphragm, they compress the carbon dust, which changes its resistance. By running a current through the carbon, the changing resistance changes the amount of current that flows.