This report describes procedures to be used for the prediction of noise irnrnission in areas adjacent to industrial plants. The proposed method has been developed as the central part of a joint Nordic research project on environmental noise from industry, coordinated by NORDFORSK. Methods for source data acquisition and immission measurements are decribed in other reports worked out within this project.
The prediction method is an octave band method (63-8000 Hz). The real noise sources at an industrial plant are represented by equivalent monopole sources. Transmission path attenuation is estimated by means of additive corrections for spherical divergence, air absorption, reflections from vertical surfaces, screening by one or more screens, vegetation, ground effect, and in-plant scattering. The predicted immission point sound pressure levels correspond to energy mean values within the meteorological conditions specified for immission measurements (downwind).
The accuracy of the predicted noise irnrnission has yet to be verified. However, some values of expected LAeq standard deviations have been given in section 1.
The layout of industrial plants vary considerably. Even if the prediction method is intended to be a general method, a successful prediction depends on qualified engineering judgements. To describe all possible procedures in detail would leave the method impracticable. The user should have some knowledge of and experience in acoustics.