Prediction and evaluation of the low-frequency noise impact from industrial noise sources

German legislation requires an assessment of low-frequency noise in addition to the regular noise assessment for industrial plants. The detailed prediction and assessment of low-frequency noise immissions is carried out according to the administrative regulation for noise TA Lärm and the German standard DIN 45680. However, a standardised procedure for predictions of low-frequency noise does not exist. For this reason, different approaches for the prediction of low-frequency noise immissions have been developed over the last two decades. Typically, the method according to DIN ISO 9613-2 for sound propagation outside is extended heuristically to the lower frequency range. The predicted low-frequency noise level outside the room is taken as a basis for determining the noise immission level inside the room. The level of knowledge about the quality of sound propagation modeling of low-frequency noise is still debatable. A forecast method of low-frequency noise components should be on the "safe side" in terms of noise control; however, the scope of the required measures to meet the noise requirements must be comprehensible and proportionate. We present an overview of the building blocks of a forecasting process and the challenges that arise. The topic is illustrated by a practical example.