Tiny MEMS microphones can be fabricated by the thousands on a single wafer. (Source: Akustica)
MEMS microphones just plunged to the micron scale, encouraging mobile device makers to use multiple microphone arrays that can aim at the user's lips and also cancel background noise. Multiple microphone setups were too bulky and expensive before Micro-electro-mechanical system (MEMS) microphone arrays downsized them for surface mounting on printed circuit boards. Now camera modules can host multiple MEMS mics, enabling beam-steering algorithms to aim at a user's voice and subtraction algorithms to cancel background noise.
Further Reading: http://bit.ly/NextGenLog-hK9K
