scope:

This European Standard describes a test method for measuring aquantity representative of the intrinsic characteristics ofairborne sound insulation for railway noise barriers: the soundinsulation index. The test method is intended for the followingapplications:- determination of the intrinsic characteristics ofairborne sound insulation of noise barriers to be installed alongrailways, to be measured either on typical installations alongsiderailways or on a relevant sample section; - determination of the insitu intrinsic characteristics of airborne sound insulation ofnoise barriers in actual use; - comparison of design specificationswith actual performance data after the completion of theconstruction work; - verification of the long term performance ofnoise barriers (with a repeated application of the method); -interactive design process of new products, including theformulation of installation manuals. The test method is notintended for the following applications; - determination of theintrinsic characteristics of airborne sound insulation of noisebarriers to be installed in reverberant conditions, e. g. insidetunnels or deep trenches or under covers. Results are expressed asa function of frequency in one-third octave bands, where possible,between 100 Hz and 5 kHz. If it is not possible to get validmeasurement results over the whole frequency range indicated, theresults will be given in a restricted frequency range and thereasons for the restriction(s) will be clearly reported. All noisereducing devices different from noise barriers and related devicesacting on airborne sound propagation, e. g. devices for attenuationof ground borne vibration and on board devices are out of the scopeof this European Standard.