Flatulence - Loud or Silent?

So why do some farts come out noisy and others silent?

loudness = ( distance_to_others / smelliness )^2

http://www.onlineeducation.net/farts

Sometimes called “Silent but Violent.”

Does sphincter tightness have anything to do with decibel level of the fart?

No, that controls the pitch.

Excellent post/user name combo!