toyhouse March 12, 2019 02:25 AM Very interesting. It mentions white noise was reduced in a pipe and that the tech is scale-able. That leads me to wonder how/if it works with low frequency energy traveling through the air? Brian M March 12, 2019 08:49 AM Wondering if some of the reduction is about resonance rather than sound reduction? Would have been nice if the device was replaced with a non-active version, to confirm it wasn't just altering some other property of the pipe i.e. not just compared to an open pipe. lee54 March 12, 2019 10:14 AM i see a number of uses: exhaust mufflers for cars, silencers for guns, air intake noise suppression. Stomps March 12, 2019 12:33 PM It would be nice to have a quiet vacuum cleaner... guzmanchinky March 12, 2019 12:55 PM Noise pollution is a huge peeve of mine (first world problem, I know). I look forward to a day when all vehicles are electric and there is a simply way to block out 100% of sound from one's ears to sleep. windykites March 13, 2019 06:31 AM guzman, try ear plugs.The best use would be on jet exhausts. Why have they not tried this yet? guzmanchinky March 13, 2019 11:41 AM windy, I have. They still let in just enough sound to keep you awake. Expanded Viewpoint March 13, 2019 08:07 PM It sort of looks like those are spiraling channels there, but the picture resolution isn't high enough to be sure. There was a car muffler I heard about from the 1960s called Auger Power, and it had some kind of a spiral baffle inside that reduced noise quite a lot, but didn't restrict the exhaust flow. I never saw one myself, just told about them by a guy I worked with. A couple of years ago my brother got some promo for a muffler with snail shell shaped baffles in it, and they are supposed to have a good tone and have low back pressure. So we built a prototype of a modified design out of some scrap stainless steel sheet metal laying in the back yard, and now need a car to test it out on. Randy Kpar March 15, 2019 12:36 PM An interesting device. I notice that little detail is given to theory of operation. I suspect that the spiral channels put some of the sound waves into opposite waveforms- a "passive" active noise reduction that cancels out the amplitude.A truly groundbreaking technology, if it proves out. warren52nz March 24, 2019 06:00 PM It's hard to believe that this device isn't frequency sensitive. I'm guessing it uses a cancellation technique where a sound of a certain wavelength is mixed with an out-of-phase "twin" that cancels it. The twin would be produced by the geometry of the device. In that case I would expect certain other frequencies to be reinforced instead of canceled as the twin being a certain wavelength would arrive in phase and reinforce the tone. However still useful for noise that has a certain constant frequency.