Room Estimation

Jøns, Christian Suhr ; Dominguez Simon, Jose Ignacio

4. term

Acoustics and Audio Technology, Master

2016

2016-06-02

151 pages

This thesis was made in order to investigate the possibility of estimating the geometry of a room and absorption of walls based on an acoustic measurement. Due to the fact that sound pressure builds up along walls and other obstacles, investigations were made in terms of how the sound field in a room is defined and how such a sound field could be reconstructed based on measurements. What defines a sound field in a room is the direct sound and the reflections. The reflections were modelled as virtual sources and if these are placed at great accuracy, in terms of distance and direction, a good estimation of the sound field can be made. The simulated measurement used a circular microphone array in order to use array signal processing to estimate direction of arrival of the virtual sources. The stochastic maximum likelihood estimator was used for the DOA estimation. The room can then be geometrically estimated if the power of the sound field is plotted. For the absorption of the walls, the spectrum from the first order virtual sources are compared to the spectrum of the direct sound with promising results.

array ; coherent ; room ; estimation ; decomposition ; impulse response ; beamforming ; ray tracing ; geometry estimation ; absorption estimation ; image source ; virtual source ; signal processing ; maximum likelihood estimator ; genetic algorithms ; simulation ; implementation ; matlab

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