miC

Mic, short for microphone, is a device that converts acoustic energy (sound waves) into an electrical signal. It uses a diaphragm that vibrates in response to air pressure, and the vibration is transduced into an electrical current by various mechanisms depending on design. The most common types are dynamic microphones, condenser microphones, and ribbon microphones. Dynamic mics employ a moving coil attached to a diaphragm within a magnetic field; condenser mics use a charged capacitor with a movable diaphragm; ribbon mics use a delicate metal ribbon that also acts as a capacitor element. Electret microphones are a widely used subset of condenser designs that incorporate a permanently charged dielectric and typically require only small amounts of power from a preamp.

Microphones differ in polar pattern, which describes how they pick up sound from different directions. Common patterns include omnidirectional (sound from all sides), cardioid (primarily from the front), supercardioid and hypercardioid (more focused rear rejection), and figure-eight (front and back). They also vary in sensitivity and impedance, influencing how the microphone interacts with preamps and wireless systems. Condenser mics generally offer higher sensitivity and wider frequency response than dynamic mics, but require external power, often supplied as phantom power at 48 volts.

Applications vary widely. Studio and live sound use mics for vocals and instruments; broadcasting and podcasting rely on compact and boundary mics; consumer devices integrate electret or MEMS microphones for communications and voice interfaces. The development of microphones over the 20th century, together with advances in electronics and signal processing, has expanded their use across recording, telecommunications, and measurement contexts.