An array microphone uses two or more microphones to record audible sound waves in a unique way. It focuses multiple sensor elements in different positions, and uses digital signal processing (DSP) to isolate audio sources. This microphone can essentially pinpoint a speaker while moving around a room and extract that signal from background noise. Virtual polar patterns permit the microphone to process signals as if the microphone were placed at the speaker's location. Device housings can resemble dual or circular arrays, or be embedded in telephones, webcams, and other equipment.
Array microphone placements eliminate need for complicated multi-microphone setups in auditoriums or meeting rooms. They can produce output that gives a sense of space, because different sounds will emerge from different directions in a stereo playback. More are found in theaters, video, and film productions, as well as household devices like video game modules or car telephones.
While not a new technology, developments in digital signal processing have increased their capabilities. In offices, they appear as table microphones, speech microphones, and goosenecks. With Internet capabilities, they can be coupled with a web camera to help provide more naturalistic video chat and online interactions.
Devices can come cheap or high-cost for special applications. Some array microphone designs exhibit high sensitivity and other enhancements; for example, tracking speakers as they move, filtering out other people talking, or reducing noise. These devices can function without need for heavy computing power or special software. They can sometimes be mounted on a desktop or computer monitor to connect with standard cables.
Different array microphone applications suit specific purposes. For example, some might be designed in circular fashion to pick up conference meetings, while others may be used for speech recognition or security monitoring. Microphones might serve for voice control of software, computers, and even home automation devices.
While capable of picking up dictations, they are especially useful in noisy environments. Conventional microphones hear sound as one messy signal; they fail to distinguish different sources of incoming sound waves. To compensate, these types limit their reception fields to particular patterns, and rely on intelligent positioning. Array microphones eliminate these issues and essentially create smart virtual microphones that liberate speakers from orientation concerns.
The illusion of space given by the dynamic surround sound of an array microphone makes the technology a popular choice in professional audio environments. Some work independently, while others are organized in groups to provide coverage in large spaces or the individual rooms of a house. Smarter digital processing of incoming sound signals makes recording devices perform with greater precision and allows the audio equipment to better imitate the natural capability and intelligence of the ear.