Abstract: An electronic control circuit (50) of a loudspeaker (LDSK) for vehicles, for emitting at least a first acoustic signal characteristic of an alarm siren is characterized in that it comprises storage means (Flash) for storing a plurality of digital samples representative of at least a portion of a reference acoustic signal which can be generated by a sample acoustic warning device, processing means (&mgr;P) for generating, on the basis of the plurality of samples, a modulated electrical signal (S1, S2) carrying at least a portion of the harmonic content associated with the reference acoustic signal, (S1, S2) and supplying to the loudspeaker (LDSK) a corresponding driving signal for the emission of a second acoustic signal substantially reproducing the at least one portion of the reference acoustic signal.

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).