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Comment by paletoy | Hacker News Reader

When i look at the bose QuietComfort earphones - earphones that are supposed to have(according to reviews) the unique ability to greatly block non-constant noise(for example talking) - and ability that to my knowledge nobody else has, and on the other hand are really expensive($270) and beyond the reach of many, i wonder:

Would some sort a programmable(app based) headphones enable an affordable noise reduction earphones that do a great job ?

Because all in all , noise is huge problem and a huge potential market.

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No. The time to do D/A/D conversion and signal processing would just leave you with noise above the wavelength equivalent o the time loss, plus a whole bunch of spurious transients. It would sound quieter on a first impression, but probably prove more fatiguing over time due to the departure from natural noise spectra (which our brains are better at filtering)...which is exactly why I find Bose's headphones impossible to tolerate for more than a minute or two.

If you want quiet, get a pair of large close-backed headphones with good insulation, such as Sony MDR-7506. OK, so they weigh a bit more. OTOH they cost less and sound better, which is why they're a fixture in the gear boxes of location recordists.

Maybe it's your personal taaste(or that you haven't tried the right earphones) , but at least according to reviews, many are quiet pleased with a good noise cancelling tech when it's working well.

Well, you can find an audience for anything. I'm a sound engineer (mainly for film) by profession, so although I'm pretty opinionated about this my comments are based on nearly 20 years years of field recording experience.

Keyword here is definitely "sound better." Bose's headphones do not sound very good at all, though I'm not sure if it's due to the quality of the headphone driver, side effects of the active noise cancellation, or a combination of the two.

The much cheaper cost certainly helps too.

Latency is a real problem, so I don't think doing the noise cancellation in software would ever work particularly well. You almost certainly need dedicated hardware, or at least a programmable chip with a low latency connection to the headphones and all the other necessary components connected at low latency as well (some microphone(s) picking up the ambient noise, for example.)

You're certainly not ever going to do noise cancellation over bluetooth.

I bet the headphones could be much cheaper, though. Bose almost certainly wants to monetize their R&D investment and take advantage of their significant marketshare. (There are non-Bose noise cancelling headphones, but I don't see them around often.)

Ya know, Apple could add hardware to their iOS devices...

IJS...

Sure, you'll probably need dedicated low latency hardware. But that's probably relatively cheap, and shouldn't prevent apple ,or even a smaller company doing something in that area.

Cost isn't what's preventing Apple or anyone else from doing this. The patents are. They have titles like "Method and Apparatus for Minimizing Latency in Digital Signal Processing Systems".

Maybe i'm optimistic ,but building a dsp that connects to a few mics and an earphone amp using low latency adc's is protected.

And the other stuff is software, which in general is very hard to enforce patents on with torrents etc.

what?

the Bose noise cancelling in ear plugs already do the processing in a "dongle" which is at the end of the plug that goes into the phone. nothing is stopping Apple/Samsung/whatever to put this piece of hardware into the phone.

and remember the new Beats headphones that are supposed to hook into the Lightning port instead of the audio jack? THIS is the use case right there.

Bluetooth audio introduces obscene amounts of latency. Whatever that dongle's doing, it's not broadcasting noise-cancelled audio over bluetooth. It's probably something low-latency like RF.

The wireless speakers/headphones and mics supported by typical mobile phones are all bluetooth. As a result, you wouldn't be able to easily (if at all) do noise cancellation for those devices via software.

You could totally do it for wired headphones, though, if you sorted out the mic positioning problem and the processing latency problem! The processing latency issue is the big one, in my opinion. Doing it without dedicated circuitry on your iPhone without the interference of other (system or user-mode) software is gonna be tricky. A pause on the order of 3ms could be big enough to cause audible glitches in the noise cancellation or give you a headache.

We had the same idea at a hackday and built it. https://github.com/Quantisan/nullwave

We used the laptop's mic as the source of environmental sound and just flipped the signals and play them back on a headphone. Because of the distance between the laptop and our ears, the signals can't really be cancelled that trivially.

The app ended up amplifying non-noises (we had some filtering) and we could hear other people talking quietly even across a room. So we jokingly said we built a spying tool on demo.

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