What Is a Microphone?
A microphone is a component that converts a sound wave in the air (a pressure change) into an electrical signal. It works in the opposite direction to a speaker.
How Does It Work?
Sound waves vibrate a thin diaphragm; this mechanical vibration is converted into a small electrical signal through capacitance or coil movement, depending on the microphone type. This signal is then amplified.
| Type | Property |
|---|---|
| Electret/condenser | Sensitive, small, needs supply |
| Dynamic | Robust, no supply, stage |
| MEMS | On-chip, digital, phone |
Electret and Dynamic
Electret (condenser) microphones are sensitive and need a small supply (bias); they're common in embedded systems. Dynamic microphones use a coil-magnet, are robust and need no supply; they're preferred for stage/vocals.
MEMS Microphone
In modern phones and laptops, small MEMS microphones made on a chip are used; they give an analog or directly digital output and take very little space.
Where Is It Used?
Phones, headphones, voice recorders, smart speakers, stage equipment and voice-recognition systems.
Signal Amplification
A microphone signal is very weak; before use it's amplified with a microphone preamp or an op-amp, then digitized with an ADC.
Common Mistakes
- Forgetting the supply: an electret microphone won't work without a bias resistor/voltage.
- Impedance: a wrong input impedance weakens/distorts the signal.
- Noise: a weak signal line picks up interference if not well shielded.
Frequently Asked Questions
Why does an electret need a supply?+
Is a MEMS microphone digital?+
Search parts related to "What Is a Microphone?"
Find the right part by comparing price, stock and distributors.