Emma Ginder was teaching on Zoom when her class heard what sounded like her passing gas. She admitted playing a fart sound to lighten the mood, apologizing for having the maturity of a young boy.

That's a lot of air. But each fart you release isn’t exactly the same. In fact, some sneak under the radar pretty subtly, while others, well, you can hear those go off from the next room. So why do ...