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Wearing both ear muffs (whether passive or active) and earplugs simultaneously can't yield more than 36 dB noise reduction ratio (NRR), because:

it does not prevent the sound to reach your inner ear from the flesh, or your skull…

which the same answer estimates to attenuate by around -32.64 dB, or a bit higher with the skull.

Does there exist a noise-cancelling or noise-isolating helmet with a noise reduction ratio (NRR) larger than 36 dB? Or some other kind of device that aims to overcome this 36dB limitation.

I don't intend this to be a shopping question but I just want to know if the concept exists or is feasible. I tried googling but I couldn't find it, so I might not have used the proper keywords for the search.

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  • Noise can come through the bones of of your feet and legs up your spine to your cranium. Also a helmet that enclosed the whole head would still have a hole where the neck goes that would be a problem. If you need more than 33-36 NRR then you have to move farther away from the source of the noise. Apr 1 at 3:24
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    An anechoic chamber does not qualify I guess?
    – Tom
    Apr 1 at 8:02
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    I feel like theoretically one could build something, but it's so rare that "just get away from the noise" isn't an option, or isn't simpler. E.g. you could build a "whole-body ear muff," some kind of insulated suit, but it would have to be a very specialized acrivity to be worth it
    – Andy Bonner
    Apr 1 at 13:50
  • Also relevant: When is 36dB "not enough"? The quote "it can't keep the sound from reaching your inner ear" is of course out of context; it can keep some sounds from reaching you (try having a conversation!). The linked question was about gunshots. If we need better reduction, it must be for louder sounds, and there's not a whole lot that most people do very often that's louder than gunfire.
    – Andy Bonner
    Apr 1 at 14:00
  • @AndyBonner I was thinking professions such as airport ground staff, shooting range staff or race car drivers may use those kind of more advanced protection. Apr 1 at 15:25

2 Answers 2

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Possible? Yes! Feasible? No. Noise reduction works either by insulation, absorption or interference. While it would be theoretically possible to insulate your whole head, surely this would not be a practical thing. More realistically it would be possible to measure noise around your body, estimate amplitude and phase after passing your body and apply negative interference to hopefully reduce this noise. In practice this is quite hard to do, as estimating phase would be quite tricky.

It would also be theoretically possible to measure body conducted noise by implanting sensors into your head, which might allow for more exact correction of such noise. But all of this, though theoretically possible, is probably far too complicated for consumer market. I’m sure it would very well be possible to build such things in research or highly specialized contexts. But as a simple wearable device? Most likely no!

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Noise-isolating helmets have been developed, e.g. this study {1} dating back from 1991:

The new helmet provides insertion loss of over 50 dB, which is 18-29 dB more attenuation than that of the tested earmuffs in the frequency range of 1-8 kHz. It is also better (8-13 dB) than the tested earmuffs at frequencies of 125-1000 Hz, and it protects against air impurities because the air fed into the helmet is filtered.

I had missed that paper because they called that helmet a noise helmet instead of a noise-isolating helmet. But Googling "anechoic helmet" inspired by Tom's comment was helpful to find that paper.


  • {1} Pääkkönen R, Vienamo T, Järvinen J, Hämäläinen E. Development of a new noise helmet. Am Ind Hyg Assoc J. 1991 Oct;52(10):438-44. doi: 10.1080/15298669191365009. PMID: 1951055. https://pubmed.ncbi.nlm.nih.gov/1951055/
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    The abstract doesn't indicate that the helmet is noise cancelling- is that accurate?
    – Edward
    Apr 1 at 23:30
  • @Edward the abstract says "The noise attenuation properties of the new helmet were tested against pink noise in an anechoic room, jet engine noise, and low-frequency noise with the test subjects wearing a miniature microphone under the protector. The new helmet provides insertion loss of over 50 dB, which is 18-29 dB more attenuation than that of the tested earmuffs in the frequency range of 1-8 kHz. It is also better (8-13 dB) than the tested earmuffs at frequencies of 125-1000 Hz, and it protects against air impurities because the air fed into the helmet is filtered." Apr 3 at 10:09
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    Right, so no indication of noise cancelling.
    – Edward
    Apr 4 at 13:12
  • @Edward Thanks, good point, noise attenuating, not cancelling. Apr 4 at 13:27
  • First off, it seems you changed your question to fit your answer. Noise isolating is not the same as noise canceling. Second, this really isn't more than a link to a paper. It's interesting, but the answer doesn't have much to it. Also not to knock the research, but the paper is from over 30 years ago. For comparison at that time the blue LED was only theoretical we've made leaps and bounds on technology since then so there should be some analysis of the technology and potential iterations somewhere outside just the paper provided.
    – Dom
    Apr 4 at 20:38

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