What is a microphone in Audio and Video?

Definition of microphone

A microphone, mike, or simply mic, is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. Microphones are transducers that detect sound waves and produce an electrical image of the sound; they create a voltage or a current proportional to the sound signal. Telephones and radio transmitters used them. Today, they have developed through some major changes in quality.

How do microphones work?

A microphone converts sound into a small electrical current. When you speak, sound waves created by your voice carry energy toward the microphone. Inside the microphone, sound waves hit a diaphragm that vibrates, moving a magnet near a coil. In some designs, the coil moves within a magnet. The magnet produces a magnetic field that cuts through the coil. As the coil moves back and forth through the magnetic field, an electric current flow through it. The electric current flows out from the microphone to an amplifier or sound recording device.

Parts of a Microphone

A microphone contains several parts to work efficiently. Modern microphones usually have 7 parts: windscreen, diaphragm, coil, capsule, magnetic core, body, and output.

Wind Screen

It is a thin layer of foam where a person speaks. It helps to provide the best quality sound, as it stops the wind from entering the diaphragm and creating unnecessary noise in the signal. A microphone includes a circular barrier made of hard metal. The windscreen is located underneath this barrier.

Diaphragm

It is most like a person’s eardrum. When a user speaks, and sound waves enter the microphone, they hit the diaphragm and cause it to vibrate. An electric signal results from the vibration inside the microphone. It is the most crucial factor of the entire microphone to provide the best quality of sound.

Magnetic Core

It is unique to a dynamic microphone, and it also creates a magnetic field for the coil. Thus, an electric signal results from the vibration.

Coil

This part connects to the diaphragm. When the diaphragm vibrates, the coil also vibrates. Then, the coil moves back and forwards between magnets; by this movement, the magnet generates electric energy as a signal.

Capsule

In a microphone, this is where vibration turns into an electrical signal after that transforming the sound. Some microphones need a capsule to perform their work, and some do not require a capsule. Microphones can draw power from a mixer with the help of a setting called “phantom power.” You are required to check if your microphones need phantom power or not.

Body

The microphone body describes the quality of sound and specifies how long the microphone will last. A good microphone has its components organized inside its body. Thus, they can protect the microphone from drops, bumps, and other things.

Output

Microphone cables connect to this part of the device. XLR is the default cable type for microphones. The work of this three-pronged cable is to send a stereo signal. Microphone cables have different lengths available. Some microphones include outputs for 1/4” cables, and some cheaper microphones come with a default cable attached.

What are the most popular types of microphones?

The three most common types are dynamic, condenser, and ribbon microphones.

Dynamic microphones

Dynamic microphones are the most widely used microphones. They have an uncomplicated design that includes a magnet wrapped by a metal coil. A diaphragm is a thin sheet on the front end of the magnet that transmits vibrations from sound waves to the coil. The coil then transfers these vibrations to electrical wires that transmit the sound as an electrical signal. Since dynamic microphones use a plain design, they are typically durable and do not require electrical power.

Condenser microphones

Usually, audio recording uses condenser microphones because of their sensitivity and flat frequency response. Each condenser microphone includes a front plate (the diaphragm) and a backplate that is parallel to the front plate. When sound waves hit the diaphragm, it vibrates and alters the distance between the two plates, creating an electrical signal. Unlike dynamic microphones, condensers require electrical power. An internal battery provides the electrical current, although an external preamp attached to the mixing console often provides 48 volts of “phantom power”.

Ribbon microphones

Ribbon microphones have high fidelity. They contain a thin ribbon made of aluminum, duralumin, or nanofilm. Incoming sound waves make the ribbon vibrate, generating a voltage proportional to the velocity of the vibration. An electrical signal transmits the voltage. While early ribbon microphones required a transformer to increase the output voltage, modern ribbon microphones have improved magnets that provide a stronger signal—in some cases, even stronger than dynamic microphones. Though condenser microphones replaced ribbon ones, some models are still available in the market.

What do we use microphones for?

Microphones are loudspeakers in reverse. Many applications such as telephones, tape recorders, hearing aids, motion picture production, life and recorded audio engineering, radio and television broadcasting, and computers for recording voice, VoIP, and non-acoustic purposes such as ultrasonic checking use microphones.

What types of microphones are good for music?

The most common microphones for musical use are dynamic, ribbon, or condenser microphones. Most microphones in use today for audio use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone, pictured right), piezoelectric generation, or light modulation to produce the signal from mechanical vibration.

What is the most common type of microphone?

The most common type of microphone transducer is an electret condenser microphone.