Outdoor music events in urban environments face the challenge to both deliver an excellent concert experience and comply with the local regulations on sound exposure of neighbouring residential areas. If the restrictions lead to low sound pressure levels (SPL) inside the audience area, the audio experience will degrade severely as high SPL is an essential part of the concert experience. Low frequencies are propagating especially far and can be focused the least onto audience areas due to their large wavelength in relation to the size of common line array systems.
This project investigates the use of active sound field control methods for improved focusing and bounding of low frequency sound energy on the audience area while avoiding sound spill to sensitive neighboring areas. It is part of the EU Project MONICA, which explores use of smart IoT devices for applications at large scale outdoor events. Enhancing the trade-off between concert experience and neighbor annoyance will lead to more acceptance of cultural events close to residential areas limits and thus to an improved cultural life our fellow citizens.
The PhD thesis presents a large amount of original work carried out with the aim of investigating the feasibility of active noise control of the community noise from outdoor concerts, a topic of practical relevance as the impact of environmental noise and potential health issues have recently gained attention . The underlying technique, pressure matching, has already been well researched in a variety of applications, but Franz mainly focused on larger-scale applications, covering large areas or distances in outdoor conditions. The technical and organizational effort spent for these well-designed experimental studies is impressive. Three major topics are investigated: large-scale experiments of outdoor sound field control - sound propagation models for active noise control - sound propagation under varying atmospheric conditions and its impact on sound field control outdoors.
The examining committee agreed that the thesis is well-written and its technical contents clearly presented. Underlying concepts and engineering skills are strong, demonstrating that Franz has a genuine and deep understanding of all matters relating to the project and is able to execute a scientific project independently.
Congratulations to Franz on his achievement.
The project is part of the MONICA project - a 36 month Innovation Action, co-funded by the European Commission.
Supervisors: Finn T. Agerkvist, Efrén Fernandez Grande, Jonas Brunskog (DTU Elektro)