Ah, my friend that is where you are wrong. The noise that is most harmful to one's ears is in the lower spectrum and only ANC does that job well. Ear plugs, especially those with holes, dont block those low frequency noises very well. So, an in-ear system with ANC would be the best of all worlds.
I refer you to the noise attenuation capabilities of ear plugs as outlined in figure 5.4 of this article:
http://www.nonoise.org/library/ane/ane.htm
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Notice that the good attenuation STARTS above 1000hz. Now, the good folks at lightspeed have clearly pointed out the benefits of ANC in this article:
http://www.lightspeedaviation.com/c...ive-Noise-Reduction/Section-3-Airplane-Issues
Notice in their graphs that ANC works best for frequencies BELOW 1000hz. This is the frequency range of many airplane engines and is the range that, eventually, does the most hearing damage.
Therefore, the best of many worlds would be if in-ear makers (homebuilt or otherwise) would incorporate ANC into their headsets. This is why I will continue to use ear-muff style headsets until ANC is put in the earplug models.
...Just my 2 cents
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