Warning siren for vehicle

摘要

The method involves generating an electrical control signal having increasing and decreasing frequency signal portions (51, 53) whose instantaneous frequencies increase and decrease, respectively. The control signal has constant frequency signal portions (52, 54) whose instantaneous frequencies are equal to a resonant frequency of a sound production device or to a sub-multiple of the resonant frequency. An independent claim is also included for a siren having a sound production device.