This European Standard defines the acoustic requirements and the test requirements for warning horns@ bells (single and recurring sound) and whistles for urban rail vehicles as defined in the CENCENELEC Guide 26@ i.e. metro systems@ trams@ light rail@ and 'local rail' systems. Additionally@ the requirements for 'tram/trains' are included. NOTE The requirements for audible warning devices for mainline rail are found in prEN 15153?C2.