Passive or active noise reduction? Jun 21, 2016 9:28:09 GMT Quote Select PostDeselect PostLink to PostMemberGive GiftBack to Top Post by admin on Jun 21, 2016 9:28:09 GMT K'asq has a very effective passive noise-canceling system that reduces 40% noise pollution of the environment.This result depends on the earplug size and your ear morphology.