Many frogs sing near a pond in the city center. Sound recording at 2 meters. Sound of a waterfall in the background. UCS Category: AMBSwmp. Duration: 01:30.
Civil siren of the "national alert signal" if the alert is over. 1 cycle of 30 seconds.
This is a realistic montage made using this imperfect sound, so feel free to do the same to make your siren sound like what you have in mind: bigsoundbank.com/national-alert-signal-remalard-61-s3257.html. UCS Category: ALRMSirn. Duration: 01:18.
Sound of a very large industrial switch. Like that of a shed or a very large room. Like you hear in the movies. This sound was created on a computer, with a switch noise, iron bar and reverb. UCS Category: MECHClik. Duration: 00:03.
This is a sound file to calculate the speed of sound propagation in air. Two microphones 1 meter apart and a movie clapperboard to generate a sharp sound. Follow this tutorial to perform the experiment: lasonotheque.org/education-sonore-f4.html#propagation. UCS Category: TEST. Duration: 00:01.