From Simple English Wikipedia, the free encyclopedia
A
microphone
, sometimes referred to as a
mike
or
mic
(both
IPA pronunciation
:
[ma?k]
), converts
sound
into an
electrical signal
.
Microphones are used in many applications such as
telephones
,
tape recorders
,
hearing aids
,
motion picture
production, live and recorded
audio engineering
, in
radio
and
television
broadcasting and in
computers
for
recording
voice.
Sound
passes through the air in waves, and as was said above, the microphone turns the sound wave into an electrical wave. Different kinds of microphones will turn the sound waves into
electricity
in different ways.
[1]
- Carbon button
- This is the first kind to become commonplace, being used in most 20th century telephones. Sound waves, by compressing and decompressing a piece of
carbon
, change the amount of
electric current
flowing in the wire, thus creating electrical waves. This kind became rarer late in the century, due in part to lack of
high fidelity
.
- Dynamic
- This uses a round plastic or rubber disk connected to a wire coil in order to turn sound into electricity. The sound wave hits the disk which vibrates as a result. This vibration moves the coil back and forth near a magnet very quickly in order to create an electrical current. The dynamic microphone is the exact opposite of a speaker which uses an electrical current to move the coil, which moves the disk. Then the disk makes sound.
- Ribbon
- This is similar to a Dynamic microphone. A thin, small sheet of metal (tin or aluminum usually) hangs between two magnets. When sound hits the thin piece of metal, the metal vibrates. That vibration creates an electrical signal in the metal.
- Condenser
- This uses two small metal plates to create an electrical current. Basically two small metal plates are placed very near to each other and electricity is run through the plates. This creates an
electric field
between the two plates. When sound hits these plates, the plates vibrate. The vibration makes small changes in the electric field. These changes create the electrical signal.
- Crystal
or
ceramic
microphones use
piezoelectricity
.
A pop filter (or pop shield) is often used in
recording studios
. It is an
electronic filter
that reduces or eliminates 'popping' sounds caused by fast moving air (such as air from the mouth).
The first microphones were invented as
telephone
transmitters. They included liquid and dynamic designs. Carbon transmitters were later used in this and other applications.
[2]