A brand new macbook box is so tight that lifting the lid won't open it; you have to wait for the bottom to slide out and drop. This results in a vibration that sounds a lot like a strange fart sound.
Aleteo frazadas (bruto). Wav. Messing around with my bed covers, wanting to create a flapping sound. Recorded with a single lom usi pro microphone on a mixpre6.