Invention of the telephone
The carbon microphone 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.
Valve microphone
In the late 1920s, Dr. Harry F. Olson of RCA began development of the ribbon microphone, eventually using permanent magnets. In 1931, nine months after the introduction of Western's 618 dynamic, R.C.A. marketed a bi-directional ribbon microphone, the 44-A. The smooth, less sibilant sound of the ribbon and its elegant styling made it the standard for broadcasters into the 1940s. The design was updated with improved magnetic material in the mid thirties with the 44-B/-BX, which maintained its production until the mid 1950s. Ribbon microphones are still in demand today and come in many styles.