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• Device use to convert sound waves into electrical signals.
• Consists of diaphragm located at the head of microphone and other components.
• Commonly used in day-today life in telephones, tape recorders, radio and television broadcasting.

Working:

• Diaphragm is made up of thin piece of material such as paper, plastic or aluminium.
• Diaphragm vibrates when it is strucked by sound waves.
• This causes other components in microphone to vibrate.
• These vibrations are converted into electric current which becomes audio signals.

Types:

Dynamic Microphones

• Consists of induction coil, magnet and a plastic diaphragm.
• It uses electromagnetic principle to convert sound energy into electrical energy.
• Diaphragm is attached to the coil, between two magnets which makes it enclose in magnetic field.
• When sound hits the diaphragm it vibrates and creates an electric current.
• This electric current is too little to make a sound so it is passed to sound amplifier to increase the strength.
• Less expensive and not efficient quality of recording.
• Used in recording of drum, guitar and other musical instruments.

Condenser Microphones

• Capacitor is used in it to convert acoustical energy to electrical energy.
• Capacitor consists of two conducting plates inside the microphone, one is fixed and other is free to move made up of very light material that acts as a diaphragm.
• Diaphragm vibrates when it is struck by sound waves, this changes the distance between two plates and creates a change in the capacitance which produces electric current.
• Expensive than dynamic microphones since quality of sound is better.
• Used in studio recording.

Microphones are also classified depending upon the audio capturing patterns as

Omni directional:

• Captures sound from all the directions.
• Best suited for group discussion and for good quality sound, mic should be held near.

Unidirectional:

• Captures sound from a specific point and blocks surrounding noise.
• Great for focusing on specific sound like recording drum beats in studio.

Cardioid:

• Captures sounds mostly from front, some from side and bit from behind.
• Pattern shape is somewhat heart-shaped.
• Used in handheld microphones.