Microphone
German inventor Johann Philipp Reis designed an early sound transmitter that used a metallic strip attached to a vibrating membrane that would produce intermittent current. Better results were achieved with the "liquid transmitter" design in Scottish-American Alexander Graham Bell's telephone of 1876 – the diaphragm was attached to a conductive rod in an acid solution. These systems, however, gave a very poor sound quality.
The first microphone that enabled proper voice telephony was the (loose-contact) carbon microphone. This was independently developed by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent (after a long legal dispute) 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. The carbon microphone is the direct prototype of today's microphones and was critical in the development of telephony, broadcasting and the recording industries. Thomas Edison refined the carbon microphone into his carbon-button transmitter of 1886. This microphone was employed at the first ever radio broadcast, a performance at the New York Metropolitan Opera House in 1910.
In 1916, E.C. Wente of Western Electric developed the next breakthrough with the first condenser microphone. In 1923, the first practical moving coil microphone was built. The Marconi-Sykes magnetophone, developed by Captain H. J. Round, became the standard for BBC studios in London. This was improved in 1930 by Alan Blumlein and Herbert Holman who released the HB1A and was the best standard of the day.
Dictation machine
Besides being far easier to handle, the wax recording medium also allowed for lengthier recordings and created superior playback quality. Additionally the Graphophones initially deployed foot treadles to rotate the recordings, then wind-up clockwork drive mechanisms, and finally migrated to electric motors, instead of the manual crank that was used on Edison's phonograph. The numerous improvements allowed for a sound quality that was significantly better than Edison's machine.
Shortly after Thomas Edison invented the phonograph, the first device for recording sound, in 1877, he thought that the main use for the new device would be for recording speech in business settings. (Given the low audio fidelity of earliest versions of the phonograph, recording music may not have seemed to be a major application.) Some early phonographs were indeed used this way, but this did not become common until the mass production of reusable wax cylinders in the late 1880s. The differentiation of office dictation devices from other early phonographs, which commonly had attachments for making one's own recordings, was gradual. The machine marketed by the Edison Records company was trademarked as the "Ediphone".