Active noise canceling only works if the speaker and microphone are both located exactly where the ear hears the noise. I don't think you can get your dog to wear the headphones.

Also, the algorithms usually cancel steady predicible noise like an engine-hum very well, but a surprise noise like thunder can't be cancelled.

Maybe you could use regular foam soundproofing on your dog's crate with some good results.

Thanks, hrench. I was afraid that might be the case. I've read that the needed amount of insulation would turn the crate into an airless chamber, though I suppose one could pump air in and out fairly inexpensively. (Bet there's a used CPAP that would take care of that part of the problem.) It's sure worth testing for those folks with easily frightened dogs. My own labs hear the thunder and they just snore. My friend's dog goes wild, both emotionally and gastrointestinally. Not pretty. But at least you have taken one approach off the table. Thanks again. BG

i agree that this is possible, as i have seen products which perform both of the tasks which Hrench objects to, i have seen an ambient noise cancellation system, though i admit it was complex and most likely too costly for your purposes, it worked especially well on base sounds, i assume due to their long period and non-directional perception, and i have used sound cancelling ear-muffs for construction which specialize in the sudden sound of a pounding, and those gunpowder powered nailguns. so though it may be too costly or complex for your application, i conject that this is possible, and i suggest further research.

i agree that this is possible, as i have seen products which perform both of the tasks which Hrench objects to, i have seen an ambient noise cancellation system, though i admit it was complex and most likely too costly for your purposes, it worked especially well on base sounds, i assume due to their long period and non-directional perception, and i have used sound cancelling ear-muffs for construction which specialize in the sudden sound of a pounding, and those gunpowder powered nailguns. so though it may be too costly or complex for your application, i conject that this is possible, and i suggest further research.

Ahh, conflicting opinions. This is good. I certainly have found noise canceling earmuffs in a price range that many serious dog-lovers would find acceptable (around $150.) So if it were possible to amplify the output of those earmuffs, blast the anti-noise into the dog's crate, and maybe isolate the crate enough acoustically, well, it just might be worth trying. I have designed the perfect test using my Labs (who don't respond to thunder, period) -- I'll put them in their crate, turn on the noise canceler, and open the treat jar. Or, for a more base note, their food bin. If it works, I'll put the whole thing on YouTube. If anyone knows how to amplify the output of those earmuffs, I'd love to hear about it. So to speak. I have this vision of a mike on a stand, wearing earmuffs.

drewanhant, I scoured the web trying to find noise cancelling other than in headsets, but all I found was mixed up people trying to associate 'active noise control' with 'noise cancelling' ANC can be done at the source of the sound, so it works, but wouldn't solve the dog-crate problem and would only cancel one sound, like the jet-engine but not the thunder. Honda discussed this for a car interior in 2004, but doesn't mention it now. Reviews weren't good. Wikipedia discusses it, but says more-or-less that it's really difficult to cancel noise in spaces.

http://en.wikipedia.org/wiki/Active_noise_control

As for cancelling surprise noises, since these systems use fast forier transforms to create the 'negative' noise, I can't understand how you could be right--how would you predict the function of the wave to cancel? ?Maybe it can adapt really quickly and miss the first 50msec and cancel the rest? Most of these aren't terribly fast at reacting. Also, if they could cancel unexpected noise, they would cancel speech, which they do not.

Tell me more about what you know. I don't say you're wrong, I just don't understand.