Microphones

A microphone is a device that turns acoustic sound into electrical energy. This is usually done via a sensor or transducer that detects the vibrations of acoustic sound and turns it into an electrical signal. Microphones are used on telephones, for hearing aids, for tape recorders, for megaphones, for radio and television broadcasting, for live PA purposes, for motion picture sound recording, and for audio engineering.

The modern microphones in use today usually use electromagnetic induction, capacitance change, or piezoelectric generation to produce an electric signal from the mechanical, acoustic vibrations. Two of the most common types of microphones are the dynamic microphone and the condenser microphone.

Microphones are made by many different companies. One of the most common uses for microphones is on stage or in the studio recording singers and musicians. Almost every song you hear on the radio requires the use of a microphone to record the vocals and some of the instruments. Also, when bands or singers perform live, they need a microphone to take sound into the sound system.

Most professional microphones utilize a three pronged adapter called an XLR to connect to a cable, but some cheaper consumer microphones use a ¼ inch jack. Microphones used for live sound reinforcement are usually outfitted with wind screens to keep the wind from interfering with the sound coming into the microphones.  Similarly, microphones in the studio are often outfitted with “pop” filters that filter out the pops made by the human mouth when the letter “P” is sung or spoken into the microphone.

Some microphones, such as those for general use, are rather inexpensive, including some unidirectional microphones. However, professional microphones that are used in large studios or for professional music recording can cost thousands of dollars.