Over the years these microphones were developed by several companies, most notably RCA that made large advancements in pattern control, to give the microphone directionality. Olson, who essentially reverse-engineered a ribbon speaker. ДЄlso in 1923, the ribbon microphone was introduced, another electromagnetic type, believed to have been developed by Harry F. This was improved in 1930 by Alan Blumlein and Herbert Holman who released the HB1A and was the best standard of the day. Round, became the standard for BBC studios in London. The Marconi-Sykes magnetophone, developed by Captain H. In 1923, the first practical moving coil microphone was built. Wente of Western Electric developed the next breakthrough with the first condenser microphone. Humphrey Bogart, Jack Brown, and Lauren Bacall with RCA Varacoustic MI-6203 ribbon microphones during World War II broadcast to troops overseas. These systems, however, gave a very poor sound quality. Better results were achieved in 1876 with the ' liquid transmitter' design in early telephones from Alexander Graham Bell and Elisha Gray вЂ“ the diaphragm was attached to a conductive rod in an acid solution. In 1861, German inventor Johann Philipp Reis built an early sound transmitter (the ' Reis telephone') that used a metallic strip attached to a vibrating membrane that would produce intermittent current.

In 1665, the English physicist Robert Hooke was the first to experiment with a medium other than air with the invention of the ' lovers' telephone' made of stretched wire with a cup attached at each end. Some of the first examples, from fifth century BC Greece, were theater masks with horn-shaped mouth openings that acoustically amplified the voice of actors in amphitheaters. The earliest devices used to achieve this were acoustic megaphones. In order to speak to larger groups of people, a need arose to increase the volume of the human voice. 5.3 Cardioid, hypercardioid, supercardioid, subcardioid.Microphones typically need to be connected to a preamplifier before the signal can be recorded or reproduced. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field the condenser microphone, which uses the vibrating diaphragm as a capacitor plate and the contact microphone, which uses a crystal of piezoelectric material. Several types of microphone are used today, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal. They are also used in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic sensors or knock sensors. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, radio and television broadcasting.

A microphone, colloquially called a mic or mike ( / m aЙЄ k/), is a device вЂ“ a transducer вЂ“ that converts sound into an electrical signal.

Microphone is picking up output sound