Acoustic Beamforming Algorithms and Their Applications in Environmental Noise

Purpose of ReviewRather than broadly investigating the beamforming field, the present work has the distinctive feature of analyzing the most common algorithms through both a theoretical presentation and a report of their most recent applications to real cases. The intent is to take a step forward towards the harmonization of the sector with a combined approach that could prove to be useful for academics willing to understand the theory and for technicians needing to choose the best algorithms to use in different measurement conditions.Recent FindingsIn recent years, the sector has seen the growth of studies published on the use of beamforming techniques and their applications to real cases. Unfortunately, different authors and research groups developed so many different algorithms that a literature review turns out to be essential to increase awareness and to avoid confusion for both scientists and technicians.Nowadays, acoustic cameras have been proven to be powerful instruments that combine a video acquisition with a microphone array to obtain real-time information about the location of noise sources. Different beamforming techniques can be applied to sound signals allowing their visualization or distinguishing the contribution of multiple different emitters. This quality, historically used in different branches of acoustics, is now spreading into environmental noise protection, especially where it is needed to locate the emitters or to better study sources that have not yet been characterized. Acoustic cameras can also be used to identify the responsible for noise limits exceedings at receivers when traditional microphone measurements are not enough, or to identify potential leakages occurred in the installation of noise abatement measurements.