Several beeps of an active sonar. This is a low frequency sonar (long range but low definition). It is a sine wave of 1190 Hz frequency easy to put in loop. In reality, a military submarine usually has passive sonar, more sonar info: en.wikipedia.org/wiki/Sonar. UCS Category: BOATSub. Duration: 00:21.
Two helicopters landing and taking off one after the other. Sound recording during the open day of the UIISCI in Nogent-le-Rotrou in France. UCS Category: AEROHeli. Duration: 02:50.
Noise of a helicopter. Recording from outside. Wind noise in the paddles. Acute and powerful sound. Sound is difficult loopable. UCS Category: AEROHeli. Duration: 00:05.
Telephone tone when the phone rings, in the UK, Ireland, New Zealand and many other countries with historical ties to the Commonwealth. These are two sound waves of frequencies 400 Hz and 450 Hz sinusoidal. This sound is easy to loop. UCS Category: COMTelph. Duration: 00:30.
Center of the town of La Loupe (28) after the start of the Tour d'Eure et Loir: Few cars, dismantling of equipment. UCS Category: AMBSubn. Duration: 02:37.