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.
Archie Frederick Collins
Collins was granted U.S. patent 814,942 on March 13, 1906 for an arc-transmitter improvement which separated the telephone microphone circuit from the arc circuit, to avoid the problem of the arc current burning out the microphone. Although this was merely an incremental improvement on existing arc-transmitter technology, the company's stock promotion advertisements claimed this patent was "a broad one, covering the fundamental principles for transmitting and receiving articulate speech without connecting wires" that was supposedly "considered by the highest authorities on patent law to be one of the strongest to be issued since the one granted to Bell in 1876". (Early purchasers of Bell telephone stock had reaped fortunes, so it was a common tactic for early radio company stock promotions, aimed at impressionable "get-rich-quick" buyers, to suggest that similar increases would occur).