Evaluation of impact noise in wooden buildings

Buildings with wooden floor constructions and wooden buildings, like prefabricated single family houses, have a long tradition in Germany. From the middle of the 1990s, additionally, multi-storey houses of wood construction have been allowed in many European countries. In general, those multi-dwelling houses have to fulfil the same acoustic requirements as concrete buildings. Especially the impact noise requirements can be difficult to meet. Even when they are fulfilled, the main complaints in wooden buildings are due to low frequency impact noises. The weighted impact noise level does not take into account frequencies below 100 Hz, and the spectrum adaption term CI can only consider frequencies down to 50 Hz. It is not clear, if subjective judgements are influenced by frequencies below 50 Hz. It is obvious, that the weighted impact noise level does not agree to subjective judgements. Additionally, the tapping machine has a different excitation characteristic than real walking people and other sources of impact noise. In the research project "AcuWood", the impact noise of wooden floor constructions are investigated. By measurements, listening tests and questionnaires it is intended to find descriptors for impact noise, which highly correlate to the subjective evaluation.