Verfahren zur Abstrahlungsanalyse mit Kugelmikrofonarrays

Diploma thesis (4.387 KB pdf)

This diploma thesis is about the development and testing of methods applicable for the analysis of radiation patterns from real-world instruments. The goal is the estimation of geometric parameters of the radiation-patterns from instrumental sounds. These parameters shall be gained from recorded sound-radiation data that have been captured by surrounding microphone arrays and shall be applicable to analysis and re-synthesis.

At first, solution strategies for different problems are developed that arise in the recording process of surrounding microphone arrays. For example, the proper rotation of the analysis using a spherical microphone array of unknown orientation belongs to those problems. Especially, a major goal is to find simple measures for detecting the acoustical centre of a sound source inside the microphone array. For a decomposition of the measured data into spherical harmonics we assume a limited spatial bandwidth due to the finite number of angular discretized microphone positions. This assumption may lead to problems in case of a sound source that is not perfectly located at the centre of the array. A cost function shall be minimized in order to find a centre of decomposition that is superior for decomposition in the analysis.

Further the tracking of a rotating sound source using correlation measures will be investigated. Here, successive sound-radiation data is set in relation. Based on the assumption that real-world instruments are not rotating in large angles on a sudden, the survey of the correlation measure can be reduced to a certain surrounding area of the actual position.

Concluding a possible set of parameters for analysis/synthesis purposes will be proposed.