This European standard defines warning horn requirements which deliver the required audibility of approaching high speed trains and conventional trains, excluding road, metro and self-contained systems. For this purpose, the following requirements are included: functional and technical requirements of the warning horn as a component, functional and technical requirements of the integration of warning horns into the vehicle, and test requirements. Operational requirements for warning horns have been excluded. NOTE The requirements for the control of warning horns can be found in EN 16186 2.