My baby is SO LOUD. when they sleep.... Is this normal ?

Where did the phrase "sleeping like a baby" come from? A sleeping baby isn't exactly quiet?

Turns out, those piglet like, snoozing sounds are a symphony of their tiny nasal passages at work! Newborn babies breathe through their noses, which allows them to eat and breathe at the same time. Their tiny airways can get a bit congested, causing a lot of grunts, groans, whistles, and squeaks. While most sounds are normal, keep an ear out for rapid breathing, grunting with widened nostrils, extended exhales, or wheezing, as they might signal something more.