State-of-the-art Analysis of Beamforming using Microphone Arrays with Near-Field Broadbanding for Acoustic Applications
This literature review concerns the application of near-field beamforming techniques using microphone arrays to tackle acoustic problems. An overview and state-of-the-art analysis of beamforming are presented.
Recently, researchers have developed robust beamformers using region-based algorithms, using constrained optimisation and by performing a maximum likelihood estimation. Because robustness is a very practical concern in beamformer design, the measured directivity of practical microphones is of interest. Microphone responses can not be neglected when designing beamformers.
As an alternative to linear microphone arrays spherical microphone setups can be used for near-field beamforming.
State-of-the-art design techniques include a total-least squares approach (TLS) that uses eigenfilters, subspace-based methods for use with spherical microphone arrays and time-space complex envelope techniques for use in acoustics.
Lastly, it is noted that real-world performance of beamforming algorithms can drastically vary from their theoretical performance and even from tests in an an-echoic chamber.
In conclusion state-of-the-art research focuses on spherical microphone array setups and a variety of algorithms to design robust beamformers for near-field acoustic applications. New algorithms and techniques should be designed for robustness and this should be verified using real-world experiments.Literature_review_for_EE4C01