Messung und Analyse von zeit- und ortsabhängigen Raumimpulsantworten

Gerhard Thallinger

Diplomarbeit (7.9 KB pdf file) März 2002

The task of this work was the measurement and analysis of room impule responses (RIR). The range in the time and frequency domain was determined over which reproducible measurement results are obtained for the acoustic transfer function.

The SDR (signal-to-deviation ratio) is used as the yardstick to evluate the measurements.

The temperature represents a central influence factor with respect to the RIR, because a temperature change within a few tenths of a degree causes a substantial modification of the RIR.

The RIR for slowly variable spaces (for example slowly opening of a window) is measured and analysed.

Furthermore, a time-varying transfer function was measured with a microphone array to generate a data record which can be used for future applications. It was necessary to pay attention to the reproducibility of the array measurement, in order to be able to establish the correspondence between the impulse response and the modification of the room.

On the basis of these data, it was analysed whether the process of the time-varying RIR can be linearly predicted. The result of the prediction experiment allows to say that time-varying RIRs can be predicted over a spatial horizon of approximately 0,05 wavelengths.