This document specifies the measurement method and conditions to obtain reproducible and comparable noise levels on-board all kinds of vehicles operating on rails or other types of fixed track, hereinafter conventionally called “unit”, except for track maintenance vehicles in working modes. NOTE – For constant speed tests the concept of “comparability” needs further caution, as this term is used as well to classify the measurement precision grade related to track roughness and track decay rates given in this document. Nevertheless, the measurement may be acceptable as type test on a track of controlled acoustic quality, but not compliant to the track specification given in this document. This document is applicable to type testing. It does not include all the instructions to carry out monitoring testing or evaluation of noise exposure of passengers or drivers over a whole journey. This document is not applicable to guided buses. It provides measurement procedures for vehicle interior noise: – when the vehicle is moving at constant speed; – when the vehicle is stationary; – when the vehicle is accelerating or decelerating; – in the driver's cab when an external warning horn is sounding. NOTE – In general, a vehicle type acceptance test would require only a selected subset of these tests to be performed. It does not provide measurement procedures for: – audibility or intelligibility of any audible signals; – assessment of warning devices other than warning horns. The assessment of noise exposure of train crew due to operational conditions is not in the scope of this document.