The 645 Siren Element Module of the Signal Tower KombiSIGN 71 with self-adjusting sound output offers new perspectives. By means of continuous noise level measurement, the alarm adjusts its sound output to 5dB above the ambient noise level. It drowns out the ambient noise level by emitting a sound level which is well audible without being irritatingly loud. Therefore, people in the siren's vicinity are not subjected to excessive noise exposure whilst optical visibility of the signal's is maintained.