Decibel

Decibel (2022) is a South Korean action thriller you can watch online on iFILM, built around one nasty premise: bombs that go off when the noise gets too loud.

An anonymous caller tells a former naval officer (Kim Rae-won) that he has planted sound-sensitive charges across the city — at a packed football stadium, inside a water park. Each one detonates the instant ambient noise climbs past 100 decibels, so you can't defuse them in silence and you can't hush a crowd. Behind the whole thing sits a submarine disaster from exactly a year before. Lee Jong-suk plays the man on the other end of the line, with K-pop star Cha Eun-woo in the cast.

Director Hwang In-ho keeps the gimmick honest — the louder the scene, the closer the blast — and that alone carries a tense ride. A good pick if Train to Busan left you hungry for more Korean genre cinema. Stream Decibel online on iFILM.