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.
Georg Neumann
Other important microphones introduced by Neumann during the immediate postwar period included the M 49 and M 50, both based on designs researched and engineered at the NWDR in Germany. The M 49 used the M 7 capsule in a configuration whose directional pattern was remotely controlled, the first microphone to offer such a feature. The M 50 featured a small, diffuse-field equalized pressure transducer embedded in the surface of a 40 mm hard plastic sphere, which gave it increasing directionality above the mid-range frequencies. The company also produced equipment for electroacoustic measurement, including calibrated measurement microphones and chart recorders.