DIN EN 50849:2017-11

This standard applies to sound reinforcement and distribution systems to be used to effect a rapid and orderly mobilization of occupants in an indoor or outdoor area in an emergency, including systems using loudspeakers to broadcast voice announcements for emergency purposes and attention-drawing or alarm tone signals. This European Standard specifies the performance requirements for sound systems which are primarily intended to broadcast information for the protection of lives within one or more specified areas in an emergency. It also gives the characteristics and the methods of test necessary for the specification of the system. In recent years, it has been shown that the speech transmission index (STI) is the most commonly used method for determining the speech intelligibility of electroacoustic emergency warning systems. Other methods are rarely used. For this reason, it has been decided to describe the required speech intelligibility using the STI scale. The responsible committee is DKE/UK 713.1 "Gefahrenmelde- und Überwachungsanlagen" ("Alarm and surveillance systems") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.