: In some versions, pressing 6 may activate dual-tone patterns or additional warning signals. HK620 Sound Effect IC with 6 Siren Sounds - Futurlec
The classic two-tone European signal (Martinshorn style) often used by police and ambulances. Hansch Typ 620 Siren Pack V1
, which is one of the most widely used electronic sirens for emergency vehicles in Germany. Key Features of the Hänsch Typ 620 System Standard Tone Sequences : In some versions, pressing 6 may activate
M. Hansch, T. Richter Affiliation: Hansch Akustik GmbH, Department of Applied Signal Systems, Aachen, Germany Publication Venue: Proceedings of the 8th International Conference on Emergency Acoustics and Public Warning Systems (ICEA 2025) : In some versions