There are a number of synonyms for the phrase "falls silent." One might say that a room "quiets," or that a person "stops speaking." Another option is to use a more poetic description, such as "the silence descends" or "the noise fades away." Other potential synonyms include "becomes hushed," "subdues," or "lapses into quiet." Regardless of the phrasing used, the general meaning remains the same: a previously noisy or active environment suddenly becomes still, quiet, and peaceful. This can happen for a variety of reasons, including a shift in mood, an unexpected event, or a simple desire for calm and tranquility.