The basic principle of a microphone is to convert sound into an electrical signal which can then be amplified. There are many uses of the microphone, some of which we use every day like telephones and hearing aids, and others which are used for entertainment purposes such as television and Music concerts.
While they have been primitive examples of microphones used since ancient Greece, the modern microphone as we understand it today was developed in 1877 by the Englishman David Edward Hughes. The basic technologies which were developed by Hughes, and by Thomas Edison in United States, greatly reflect modern microphones which are still used today.
The ribbon microphone uses a thin metal strip, connected to the output, and the vibrations along this strip generate the electrical signal. Another type of microphone and the earliest type of microphone is the carbon microphone. In this example, minuscule pieces of carbon vibrate between two plates to generate the sound which is charged with a small bolted enabling them to be converted into an electric signal.
One of the most common types of microphone news today, especially in television broadcasting, is the fiber-optic microphone. The fiber-optic microphone uses fluctuation in the intensity of light to create the electrical signals from acoustic waves. Because they use light, they are averse to being affected by changes in weather, heat, and moisture – therefore particularly favorable in outdoor environments.
Most microphones require a power source to be operational. Throughout the 1960s different methods for powering microphones were explored. While it used to be common to see microphones attached to a wire, today most are battery-powered and use a system known as phantom power.