Microphones are a part of everyday life. They are used in telephones, transmitters for commercial radio and television broadcast, amateur radio, baby monitors, tape recorders, motion pictures, and public address systems. There are many different types of microphones—the design depending upon the application. Sound recording, radio and television, and motion picture studios use ribbon or condenser type microphones because of their high quality reproduction of sound. Public address systems, telephones, and two-way radio communications systems can use carbon, ceramic, or dynamic microphones because of their versatility and low cost.

Diaphragm is that part of the microphone which is designed to transform the vibration of sound into electricity. The vibration of different types of sounds vibrates the diaphragm. differently. This vibration makes the diaphragm move to and fro in the magnetic field. As a result, alternating electric current is induced in the moving coil. Thus microphone converts the sound energy into electrical energy. This is called audio signal. Having amplified, this electric audio signal can be transferred to a long distance through a telephone line or radio So microphone plays a vital role in television and radio broadcasting, recording and telephone.

Construction is simple and comparatively sturdy. 
No power supply is required. 
Relatively inexpensive.

Good sensitivity at all frequencies. 
Power supply is required. 
Vulnerable to structural vibration and humidity.

Often during recording, a "pop shield" filter is required to protect against noise caused by the vocalist's breath hitting the condenser microphone. This is because condenser microphones are able to react to more subtle sounds. On the other hand, condenser microphones are not suited for high-volume recording, so dynamic microphones are mainly used in situations where loud audio is to be picked up.

Wireless microphones can be moved around freely, without the cables getting in the way. These microphones require a transmitter and a receiver in order to broadcast sound. In general, handheld wireless microphones contain a built-in transmitter, whereas headset and clip-on microphones include a cable that attaches to the belt-pack transmitter.

The transmitters for both types are powered by batteries (either dry-cell or rechargeable), so always make sure that ample battery power is available.

It's also necessary to set the transmitter of the broadcasting microphone and the receiver to the same channel. Make sure that when you are using more than one wireless microphone, the transmitting and receiving channels are set differently for each microphone.

Microphones worn on one's head are called headsets, while microphones worn on clothing not far from one's mouth are called lapel (or lavalier) microphones. Either can be used so that both hands are free. Headsets are often used while singing or dancing, while lapel microphones are often used by presenters on television. These headsets and lapel microphones are often used wirelessly.

Note: Many headset and lapel microphones are omnidirectional, so extreme caution should be applied when using them with PA systems. Try using a unidirectional headset microphone to reduce the risk of feedback.