Noctua shows prototype of Active Noise Cancellation HSF

It works much in the same way as noise-cancellation in premium headphones and smartphones. A mic inputs noise from the cooler, speakers give out the same noise with a phase difference, this causes destructive interference between noise coming from the speakers and the cooler, and noise is reduced. The speakers are positioned along each of the two fin-stacks. The mics are just as discrete. Noctua stuck a mic into the test chamber with the cooler running, and visitors couldn't hear a thing, at least nothing that's louder than the morning crowds at Nangang, after the event has been opened up to the general public.