for a female or post-op transsexual to harbor a pocket of air in the vaginal canal and release said air while simultaneously sneezing. the force of opposing pressures may cause all said air to expel.
When a male farts sitting down. The air then escapes through the front and ripples across his sac, thus creating a sound similar to a fart w a sac twist on it.
Man, did you you hear that... Billy just squeefed in his seat and I’m pretty sure blew a hole in his zipper.