Nowadays, Microphones has become a part of daily life and played an important role.There are many famous microphone brands appearing, such as Shure microphones, Sennheiser microphones and some others. They are widely used and usually by definition has two obvious meanings: it is an instrument for intensifying weak sounds and make the sound more loud and clear. And it is a device which can transform sound waves into electrical impulses.
The history of microphone can date back to the end of the 19th century. Alexander Graham Bell and other scientists are dedicated to finding better ways to pick up the sound for improving the latest inventions - telephone. During that period, they invevted liquid microphones and carbon microphone, but the result is not satisfactory and just reluctance to use. In 1876, Emile Berliner invented the first microphone which is used as a telephone voice transmitter. Microphones are used in many applications such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recorded audio engineering, FRS radios and megaphones.
The sensitive transducer element of a microphone is called its element or capsule. A complete microphone also includes a housing, some means of bringing the signal from the element to other equipment, and often an electronic circuit to adapt the output of the capsule to the equipment being driven. Microphones are referred to by their transducer principle, such as condenser, dynamic, etc, and by their directional characteristics. Sometimes other characteristics such as diaphragm size, intended use or orientation of the principal sound input to the principal axis of the microphone are used to describe the microphone.
With the development of society,microphone is continually updating for satisfying the needs of the users. The variety become more and more fruitful. According to the transducer principle,it can be divided into electromagnetic induction(dynamic-mic and ribbon mic),capacitance change (condenser microphone), piezoelectric microphone,carbon microphone and fiber optic microphone and so on. And by the transmission of electrical signals, it is split into wireless microphone and wired microphone.