As someone with disposable income working in an open office, I desperately want to know if this can be used to build something to cancel out human voices more completely than Bose QC-35s.
They also give off a very strong “I’m busy” vibe
If that’s still somehow not enough, wear these concurrently (this is great for planes too): Etymotic High-Fidelity Earplugs, ER20XS Standard Fit, 1 pair, Polybag Packaging https://www.amazon.com/dp/B00RM6Q9XW/
Also recommend the above with these foam tips for longer wear, I’ve done up to 16 hours with only a little discomfort: Shure EABKF1-10M Medium Foam Sleeves (10 Included/5 Pair) for E3c, E4c, E5c, E500PTH, i3c, i4c & SE Earphones (Black) https://www.amazon.com/dp/B0015PN3W6/
Thus I use the audio-technica MSR7 at work. At home, I don't need isolation, so I enjoy sennheiser's HD600.
Headphones with active/acoustic noise cancelling use the same trick, except that they pick up the upcoming sound waves with a microphone and then use a speaker to generate those "reflected" soundwaves.
Actually-reflected soundwaves cannot be as strong as the upcoming soundwaves, so they're never going to fully cancel out the noise. Those generated soundwaves can.
One point is that there's most likely less latency for a soundwave to get reflected vs. picked up by a microphone and then generated by a speaker. However, to my knowledge our human senses have even more latency than both of those, so I don't think that matters.
That's why they are less capable in filtering non-repetitive noises like speech, especially their higher frequencies.
1. The latency is active noise cancelling systems is very low; much less than the frequency of most sounds.
2. Noise cancelling is ineffective at higher frequencies because the space between the speaker driver and the ear becomes large enough that the destructive interference becomes imperfect.
3. The feedback has to come from somewhere, and once the frequencies become high enough, the phase shift caused by the physical distance between the driver and microphone start to affect the feedback loop.
4. Because of these issues at higher frequencies, they just lower the feedback gain at higher frequencies. This effectively makes the active noise cancellation system be not sensitive to higher frequencies.
5. This is very much akin to frequency compensation in other topics like buck converters and op amps--the additional phase shift in the feedforward path that often increases as frequency goes up becomes problematic to compensate, so they just make the feedback loop insensitive to that region.
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the quick way to debunk this is two tests:
1. Play some bandlimited noise (https://www.youtube.com/watch?v=5qV5j9wD5e8) really loudly and I guarantee you any shitty ANC headphone will cancel this out just fine. Noise by definition is non-repetitive.
2. Play a high frequency sinusoid (https://www.youtube.com/watch?v=TRKB5kWs7KE) really loudly and it will go straight through any ANC headphone. A sinusoid is as repetitive as it gets.
It's not something I would recommend. It makes me feel uneasy. A dozen people could walk up behind you and watch you work, and you'd never know until they tapped you on the shoulder. If you have any anxiety at all about this, true silence will make it far, far worse.
Noise isn't the only problem with open office layouts. It's just a convenient way to describe it to people who don't understand. If you think it's hard to talk to business people about the problems caused by excessive sound levels, imagine how difficult it is to talk to them about how you feel.
At some level, though, they do know this. Your CEO doesn't have his desk facing the door of his office because that position is the quietest. Try do-si-do'ing his desk one day and see how long that lasts.
The only down-side for me was that they are not as quick to pop on and off as regular headphones.
Recent studies are mixed as to which has a more deleterious effect on creativity, the coworkers yapping or the heavy metal.
Apparently, it can be quite difficult to determine whether the sound comes from your phones or outside them if you haven't turned the NC on.
Fifty shades of embarrassing moments, that.
Unfortunately.