Microphone used in Alexander Graham Bell's telephone.
The History of Microphones
Microphones convert sound waves into electrical voltages.
A microphone is a device for converting acoustic power into electric power that has essentially similar wave characteristics. Microphones convert sound waves into electrical voltages that are eventually converted back into sound waves thru speakers. They were first used with early telephones and then radio transmitters.
In 1827, Sir Charles Wheatstone was the first person to coin the phrase "microphone."
In 1876, Emile Berliner invented the first microphone used as a telephone voice transmitter. At the U.S. Centennial Exposition, Emile Berliner had seen a Bell Company telephone demonstrated and was inspired to find ways to improve the newly invented telephone. The Bell Telephone Company was impressed with what the inventor came up with and bought Berliner's microphone patent for $50,000.
In 1878, the carbon microphone was invented by David Edward Hughes, and later developed during the 1920s. Hughes's microphone was the early model for the various carbon microphones now in use.
With the invention of the radio, new broadcasting microphones were created. The ribbon microphone was invented in 1942 for radio broadcasting.
In 1964, Bell Laboratories researchers James West and Gerhard Sessler received patent no. 3,118,022 for the electroacoustic transducer, an electret microphone. The electret microphone offered greater reliability, higher precision, lower cost, and a smaller size. It revolutionized the microphone industry, with almost one billion manufactured each year.
During the 1970's, dynamic and condenser mics were developed, allowing for a lower sound level sensitivity and a clearer sound recording.