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.
Volta Laboratory and Bureau
The Photophone, also known as a radiophone, was invented jointly by Bell and his then-assistant Sumner Tainter on February 19, 1880, at Bell's 1325 'L' Street laboratory in Washington, D.C.