The microphone is defined as a sensor that converts sound into an electrical signal. Microphones are used in many applications. They are used in various instruments like telephones, tape recorders, and hearing aids. They are also used in motion picture production, live and recorded audio engineering, and radio and television broadcasting. Microphones are used in computers for recording vocals, and also for non-acoustic purposes such as ultrasonic scanning.



The basic function of a microphone is to capture sound waves and interpret them into electrical signals. The common signal flow is activated through the help of thin membrane producing some proportional electrical signal.

There are different types of microphones. The microphones used for live performances are not the same as those that are used in recording studios. Microphones can be generally divided into two main categories. These are condensers and dynamic. The condenser microphones function when the diaphragm acts as one plate of a capacitor, and the vibrations produce changes in the distance between the plates.

The dynamic microphone, on the other hand, works in the same manner as a loudspeaker but only the principle is reversed. As the diaphragm vibrates, the coil moves in the magnetic field, producing a varying current in the coil through electromagnetic induction.

The bass microphone is a microphone with a very large diaphragm. They usually work on the principle of dynamic microphones. They are usually employed in situations that produce very loud sound pressure levels and they are very sturdy and have lousy high-frequency response. They are typically found inside bass drums of drum sets at rock concerts.

Another microphone is the wireless microphone, which is commonly used in various Karaoke bars and stage performances. These microphones are essentially the same as ordinary microphones, only they also have a transmitter. The transmitter can be in the body of a hand held microphone, which accounts for the larger size of a wireless microphone, or in a separate belt-worn pack. Wireless microphones typically transmit on only one unique frequency per microsecond.

A 'true diversity' wireless system will have two antennae on the receiver end, which incidentally, puts out a line-level signal for the mixer instead of a micro signal. When the signal strength between the two antennae varies, the receiver will opt to receive the signal from the stronger antennae. This switching can be very rapid and is usually unnoticeable. True diversity wireless systems are usually far less sensitive to radio interference and blockage than single-antennae systems.

Lavalier microphones are another type of microphone is that is used out-doors during broadcast interviews. The lavalier microphones are the familiar 'interviewer's collar pin', which consists of a small, usually electret microphone worn at the chest, clipped to clothing. This can either be corded or wireless, though the latter is usually preferred.

The wireless version runs into a transmitter, usually worn on the belt. Battery or phantom power, depending on the make of the microphone, can power lavalier microphones. They have also been good for amplifying up wind instruments, clipped to the edge of the 'bell'.