Carbon microphone
The first microphone that enabled proper voice telephony was the (loose-contact) carbon microphone (then called transmitter). This was independently developed around 1878 by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent in mid-1877, Hughes had demonstrated his working device in front of many witnesses some years earlier, and most historians credit him with its invention.
Beyerdynamic
In the 1920s in Berlin Eugen Beyer believed that the cinema presented a new opportunity in communication media. The first products he produced were loudspeakers for film palaces in 1924. At the end of the 1930s Beyer developed the first pair of dynamic headphones. World War II temporarily froze production, however, in 1948, Beyerdynamic sought new beginnings in Heilbronn. The "Stielhörer" DT 49 became a popular item of "Plattenbars” (record-bars) in the 50’s. The "transistophone", the company's first wireless microphone, went into production in 1962. The Beatles 1966 German tour used the E-1000 microphone. Elton John, ABBA, and Stevie Wonder all sang into sound transformers produced by Beyerdynamic. In 1985, Beyerdynamic acquired its then-North American distributor, Burns Audiotronics, which became its North American subsidiary. Today beyerdynamic, Inc. have their own office headquartered in Farmingdale, New York.