Abstract

This bachelor thesis deals with the problem of flutter echoes inside enclosed spaces and possible measures to prevent them. Flutter echoes result  from repeated sound reflections between parallel walls with insufficient absorption; they are mostly perceived as disturbing and can noticeably impair speech intelligibility. After a summary of some theoretical fundamentals of acoustics and measurement techniques, measurements are performed in the interior space of the university building Inffeldgasse 16 c, Graz, regarding the general acoustic situation and the flutter echoes in the building. Trying to find valid measures for the whole space and to detect the echoes in the measured impulse responses, different problems resulting from the size and the shape of the building were encountered. A simulation of the whole building in CATT-Acoustic was created. The comparison with the measurement data shows significant differences, which again can likely be traced back to the room geometry. Finally, various possible strategies for prevention of flutter echoes, both in general and with regard to the situation in the examined enclosure, are presented and reviewed by means of simulations.

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