LANCELLE_Leo_2021_22_Creaking door.wav

Here, I generated two different sounds:
A square waveform sound with a duration of 1 second on a frequency of 440 to 1300 Hz.
A sawtooth shaped sound lasting 1 second, on a frequency of 440 to 1300 Hz.

Then I synchronized the 2 sounds together, then I simply repeated and reversed the 2 sounds to give the impression of an alarm, or a police/fire siren.

Finally, to avoid saturation of the final sound, I normalized the pitch of the 2 sounds to -9 decibels.