Microphone arrays

Microphone arrays are used to spatially localise acoustic events and optimise signal capture in one direction in a targeted way, e.g. towards a speaker. Two- or three-dimensional configurations are possible with arrays ranging from two to an arbitrary number of microphones. Arrays for a wide range of applications and designs are developed at the Fraunhofer IDMT – e.g. for ambient voice control systems, acoustic monitoring applications or signal capture in hands-free systems.

Multi-microphone signal processing

By using several microphones, it is possible to suppress sources of interference more effectively for signal capture. At the Fraunhofer IDMT, algorithms for automatic localisation, adaptive direction filtering (beamforming) and interference noise reduction are developed and adapted to specific applications. The scientists can choose from a wide range of single- or multi-channel algorithms for signal enhancement.

MEMS microphones – good transmission quality with minimum dimensions

The functional capability of a multi-channel noise reduction process depends crucially on the microphones used. In contrast to electret capsules, modern capacitive MEMS microphones offer significantly reduced production-related scatter in the transmission behaviour − with a self-noise rating in the same order of magnitude or below. In addition, digital MEMS microphones can be connected directly with signal processors. This reduces the technical complexity required for conversion.