Derivation of reference spectrums for transportation noise sources to be used in rating sound insulation

Abstract

The research project started in August 2011 in relation to COST TU 0901, aims to investigate sound insulation descriptors mainly to be proposed for Turkey's new regulation. A part of the study involves facade noise measurements conducted independently for road, railway, aircraft noises in order to obtain the reference spectrum(s) applicable in rating and design of sound insulation. Such reference spectrums can be found in literature as well as in ISO 717, however it is necessary to verify those for different sources, different source operations and traffic parameters and different built-up configurations affecting the spectral levels on building external elements. In this study, numbers of field measurements applying the ISO 1996-2 were conducted for the purpose of deriving average spectrums. Statistical values of the normalized spectrums obtained from the spectral time-histories were compared. Significance of the parameters such as approach, pass-by and move-away situations were evaluated after categorizing the data. This paper describes the results and proposes three different reference curves for normalized spectrums. © European Acoustics Association. © 2012 Elsevier B.V., All rights reserved.