Abstract: An acoustic-signal emitting device for vehicles comprises an electronic control circuit (50) for generating driving signals and a loudspeaker (LDSK). The loudspeaker includes a transducer device (1) connected electrically to the electronic control circuit (50) in order to receive the driving signals and to convert them into acoustic radiation. The transducer device (1) being a moving-coil device with a compression chamber and having dimensions such that it can generate acoustic radiation characteristic of an alarm siren in a first operative condition and acoustic radiation characteristic of an acoustic warning device in a second operative condition. A twisted horn (2) is coupled acoustically with the transducer device (1) in order to propagate the acoustic radiation emitted in the two operative conditions, outside the emitting device (100).