A Microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1876, Emile Berliner invented the first microphone 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, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors.

How Microphones Work

Microphones are a type of transducer - a device which converts energy from one form to another. Microphones convert acoustical energy into electrical energy. Different types of microphone have different ways of converting energy but they all share one thing in common: The diaphragm. This is a thin piece of material which vibrates when it is struck by sound waves. In a typical hand-held mic, the diaphragm is located in the head of the microphone. When the diaphragm vibrates, it causes other components in the microphone to vibrate. These vibrations are converted into an electrical current which
becomes the audio signal.

Advantages & Disdvantages

Wireless Microphone mg12dynamicmicsm58.jpg
The advantages are:
  • Greater freedom of movement for the artist or speaker.
  • Avoidance of cabling problems common with wired microphones, caused by constant moving and stressing the cables.
  • Reduction of cable "trip hazards" in the performance space
The disadvantages are:
  • Sometimes limited range (a wired balanced XLR microphone can run up to 300 ft or 100 meters). Some wireless systems have a shorter range, while more expensive models can exceed that distance.
  • Possible interference with or, more often, from other radio equipment or other radio microphones, though models with many frequency-synthesized switch-selectable channels are now plentiful and cost effective.
  • Operation time is limited relative to battery life; it is shorter than a normal condenser microphone due to greater drain on batteries from transmitting circuitry, and from circuitry giving extra features, if present.
  • Noise or dead spots (places where it doesn't work, especially in non-diversity systems)
  • Limited number of operating microphones at the same time and place, due to the limited number of radio channels

Unidirectional Condenser Microphones / Desktop Microphones
Advantages Desktop-Microphone.jpg
  • Can be mounted to the desk or monitor in the form of a Boom or Gooseneck. Microphones that utilize the bias power from the sound card do not need an external or battery power supply which is an advantage if you are trying to use one with an older model laptop.

  • Is typically a condenser microphone requiring an external DC power source. The sound quality is lower.

Headset Microphonesheadset-microphone-usb.jpg
  • Wearing the microphone on your head (headset) will keep the microphone at a precise distance from your mouth and will result in a more consistent recording of your voice.

  • If not a wireless headset, you are somewhat limited by the wires that connect the headset to the computer.

USB MicrophonesUSB_microphone.jpg
  • These are digital microphones that convert your speech into digitized audio without the use of a sound-card.

  • Does require use of systems that have available USB ports.