Abstract: The present disclosure discloses a noise-reducing earmuff, comprising: an earmuff shell forming an earmuff cavity; a separator being installed in the earmuff cavity and forming an independent chamber; and a conduit being installed on the separator, the conduit being provided with an opening at each of the two ends thereof; wherein one of the openings being located in the chamber, and the other extending out of the chamber and being located in the earmuff cavity; wherein the chamber and the conduit form a low-frequency resonator whose resonance frequency is equivalent to a corner frequency of a low-pass filter formed by the earmuff.