DS EN 16272-3-1:2012 Railway Applications - Track - Noise Barriers And Related Devices Acting On Airborne Sound Propagation - Test Method For Determining The Acoustic Performance - Part 3-1: Normalized Railway Noise Spectrum And Single Number Ratings For Diffuse Field Applications Defines a normalised railway noise spectrum for the evaluation and assessment of the acoustic performance of devices designed to reduce airborne railway noise near railways.