Development and application of wave based methods for building and room acoustics research in the lower frequency range.

The global concern in building acoustics is to achieve the necessary sound insulation and to create pleasant and supportive room acoustics conditions. In recent years, special interest for the performances at low frequencies (below 200 Hz) emerged. This raises major questions: how to master the sound insulation in this frequency range and how to influence the low-frequent listening experience? Both questions relate to the proliferation of relatively affordable home entertainment systems and to increased interest for lightweight, timber framed buildings and apartment houses in view of sustainability concerns. This urges to improve the techniques to predict, measure and evaluate sound-structure interaction and sound dissipation at low frequencies. The modal density is too low for the common statistical approaches. The aim is to extend the scope of my earlier research on the wave based method to more specific investigations of low frequent performances. Examples are: sound transmission through double walls with structural connections, flanking transmission, study of sound fields in coupled rectangular spaces and the further discussion on the measurement procedures. Interesting applications in room acoustics topics will be explored. The method allows for a study of the interaction between a sound field and its sound absorbing boundaries. The effect of variation in distribution (homogeneous or patchwork), location (corner or surface) and size (boundary effects) will be assessed.