Psychology says people who can sleep through loud noises aren't necessarily heavy sleepers, they may simply have brains that filter familiar sounds more efficiently

Most people have experienced waking up because of a barking dog, traffic outside the window, or a neighbor's late-night celebration. Yet some people seem completely unaffected. They sleep through thunderstorms, construction work, loud televisions, or even a crying baby in another room without realizing any noise occurred.

Friends often joke that these people could "sleep through anything." Psychology and sleep science suggest the explanation is more interesting than simply being a deep sleeper.