Microphone types and characteristics

History of microphone

In 1876, Emile Berliner invented the first microphone used as a telephone voice transmitter. At the U.S. Centennial Exposition, Emile Berliner had seen a Bell Company telephone demonstrated and decided to find ways to improve the Bell company telephone. The Bell Telephone bought Berliner's microphone patent for $50,000.

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 a microphone works

A microphone converts acoustic power into electric power, this means that if a sound is created within the correct circumference of the microphone it will be picked up and then amplified. Microphones convert sound waves into electrical voltages that are converted back into sound waves through speakers.

Types of microphone

- Dynamic

"Dynamic mics are useful when the sound source is close and reasonably loud." Dynamic mics are a common house hold mic often used for talking to people over computer software such as skype or others in which two parties can talk to each other.

- Capacitor

Capacitor microphones can respond to very high audio frequencies. They don’t need as much amplification than dynamic mics to produce the same output level, making them more suitable for quieter or distant sound sources. The reason capacitor microphones have such a good frequency response is that their diaphragms can be made much thinner and lighter than those of dynamic models, as they don't have to drag the mass of a voice coil along with them.

- Electric condenser/battery electric

- Ribbon

With the invention of the radio, new broadcasting microphones were created. The ribbon microphone was invented in 1942 for radio broadcasting.

- Carbon

In 1878, the carbon microphone was invented by David Edward Hughes, and later developed during the 1920s. Hughes's microphone was the early model for the various carbon microphones now in use.

- Crystal

These mics are based on pressure, when the pressure hits the diaphragm of the microphone it deforms the piezoelectric crystal inside which creates sound waves, this is an old form of microphone and isn’t used today due to how sensitive it was and it was incredibly easy to damage.

- Clip on mic

The clip on mic pretty much explains itself, it is a very common mic that most people would have seen on television in things like game shows when the host or contestants may have a mic clipped onto their shirt about chest height so that they do not need to hold one.

- Rifle mic

The rifle mic or shotgun mic captures the sound being produced directly in front of them and a bit behind them, they are usually used in gig atmosphere’s because they can amplify the performer’s voice or instrument and keep the sound of the audience out of the amplification so everyone can hear the performer and not the relayed amplification of the audience.

- Boom microphone

A boom mic is the one shown here on the right, they are used in professional filming work, mainly in films or other television productions and they capture sound in a high quality style.

- USB

Polar patterns

- Omni- Cardioid- Hyper cardioid- Figure of eight- Application/Purpose

References