Noise Cancelling Heaphones Experiment

[NickRobo1994]

I was wearing noise canceling headphones.....

[rohaantje]

this realy works,

we're testing this at school.

only the point is.

no speakers is the same, you'll never stand right in front of both speakers.

so you will always hear something....

(sorry for my bad english)

[abzset]

Yes everybody this is all true. If anybody knows physics and more specifically waves. They would also know of something called destructive interference. Meaning when two opposite wave forms combine they cancel themselves out. With the indiana jones picture its the same idea assuming light is a wave the two electromagnetic waves cancel out. what bose does takes advantage of the sound leaking thrue the headphones there is a little mic on each headphone that takes that sound and reverses it 180.

[pixuma]

Whoops, i mean the Bass gets VERY quiet :)

[pixuma]

This works! I was skeptical, but i just tried it in audacity! It doesn't make it go dead silent, but all the mids and highs become VERY quiet and the bass is deadened some. I did find that even a TINY adjustment in speaker distance from your head (in relation to the other speaker) does in fact make a pretty significant difference in how well this works. I also tried the image thing in photoshop, it also works!

He's not bullshitting!

[mrtoshko]

it worked! When you use headphones and bend them over so they both point to one ear and are really close, the music can still be heard (doesnt work perfectly) but its really quiet, when you move one headphone away, doesnt matter which one, its much louder! cool! lol @ the idiots that couldnt grasp this

[vandallas12345]

All you have to do is bring your speakers together and point them at each other. Obviously you won't get perfect noise cancellation because the conditions aren't right for it, Minute changes in air pressure, signal noise along the speaker wires, surrounding objects, will bounce the sound differently and negate the effect

TL;DR: place speakers 4 inches apart, facing each other

??????

PROFIT!!!!1!!!!111!

[zoomonster2]

wow dint work for me and i wasnt wearing headphones

[PeacefulVocalTrance]

this is a lie! I looked at my music mixer, and when he said "both are playing", MY MUSIC MIXER ON MY COMPUTER SHOWED NOTHING!!! NOTHING IS PLAYING!!!

[myurgil]

@PeacefulVocalTrance

Right, the end result is that nothing is playing. When both the original file and the inverted file (both in mono) were added to the movie file, the computer saw that one would cancel out the other. Therefore, when you look at your music mixer, it's looking at the end result - the audio equivalent of the grey Indiana Jones picture.  It doesn't really look like anything at all, much less a picture of Indiana Jones. Same holds true for the music.

[PeacefulVocalTrance]

@myurgil UM, NO, FUCKER, THERE WAS NOTHING TO BEGIN WITH. Stupid bitch.

[myurgil]

@PeacefulVocalTrance

Wow, you really are "peaceful", just as your screen name suggests. I'm telling you that as I created this video, which I did myself, I loaded two audio files into that sequence of dead silence. I thought I'd just be nice enough to clear up what seemed to be a little confusion, but if you don't believe me, I don't care. No one is making you watch this.

[09charleszf]

*wearing headphones* When you played the sample at the end, it sounded as if the left ear wasn't playing but then I pulled my right headphone out and i could clearly hear the left headphone.

[stcheeve]

When watching that vid on the iphone the inverted sound works... Because the iphone haves one stereo speaker... U just hear a little noise but its completely silent...

[ossumguywill]

Here's what I did to get this to work: Hold both headphones together, about a foot directly in front of your face. Then, move one back slowly and listen to the volume increase :)

[jednoucelovy]

Dear author, the noise-cancelling headphones do not simply invert the phase. That would not work due to time delay taken by processing. I suggest you take a look into adaptive filtering and signal prediction theory before posting B/S on youtube. Cheers.

[ossumguywill]

@jednoucelovy I'm fairly sure they just invert the phase.... They have dedicated analog inversion ICs (AKA comparators) with sub-nanosecond response times... Even at 10khz, the wavelength of sound is well over an inch, and at the high switching speeds possible with transistors you can get the inverted phase accurate to less that a micrometer (about a third of a micrometer with 1ns lag). This means almost perfect cancellation. Of course you could be right, this is all IMO ;)

[Frungi]

Interesting experiment. Didn't work at all for me, though, with speakers on either side of my display; the music just sounded slightly distorted, like a low-quality MP3.

[PSCocks]

Anyone know anything about the Jabra C820

[Govadina]

I used headphones and it didn't work :/

[myurgil]

If you simply watched the video while wearing headphones, than no, it won't work at all because headphones don't allow for any amount of overlap. To get the full effect of this video, it's absolutely necessary that each ear hears both the left AND right channels at the same time.

[petersin71395]

hi, which one do u think is better the qc2 or the qc3?

[myurgil]

Well, the QC2 is the only noise canceling headphone I've ever used. I prefer the around-the-ear comfort as opposed to over-the-ear. It also makes it easier for Bose to eliminate noise, as it creates a better seal. I believe they compensate for this with the QC3 with better technology, but that also drives up the cost of the QC3. There are other videos (see videos realted to this one) on YouTube that compare a wide variety of noise canceling headphone by all different manufactures.

[benstarsky]

it worked lol

[Rockbandplayer57]

that was odd

[IsaacDFP]

If you're an idiot then I don't know what I am, lol. I get the theory, but i don't get one thing... how does the headphone *create* an opposing soundwave of your entourage?

[myurgil]

The opposing soundwave sounds exactly the same as the original. The first two samples you heard are actually opposites - it wasn't just the same sound accompanied by a pretty picture. I'm not sure about all the electronics behind the headphones, but they probably just invert the sound the same way my computer did (however that was).

[blank10123]

good noise cancelling headphones have built in mics which record the ambient noise and output the antiphase audio

[TheStinkyHindu]

Don't feel like one, this is one of the worst ways to explain HEADPHONES with noise cancelling technology. The technology on what it does is explained here (crudely) but then ur naturally to think how would it work with headphones & realtime sound. The technology isnt the greatest as of yet but it monitors ambient noise in the background & then applies what is stated here (dampening effect, its not 100%). It works quite well with say someone blowdrying their hair in the background.

[flashback1234]

@IsaacDFP pretty easy. There is a microphone on the outside of the headphone cap of the headphone which picks up the outside sound. And a circuit inverts the sound waves and plays it through the speakers of the headphone. Which in result gives you silence from anything the mic picks up. Which is basically every sound not in your headphone cap. Pretty cool concept!

[callmeplzz]

Hey guys i donno if i should get the Audio-Technica ATH-ANC7 Noise Cancelling Headphones or sony MDR NC60

[Gbjerke]

I know this is a late reply..But if you still haven't decided. Get neither of. Sennheiser PXC 350 or 450. Best you'll get. Atleast what i think - Audiophile

[toutaaaaaaa]

dude youre no idiot i could have never thought of that pure 100% genius, u should work with BOSE or Sennheiser

[PatrickASneed]

I loved your visual example of noise cancelling.

I got a set of QC2 headphones and used them with my Iphone to listen to some Dire Straits while I was riding my John Deere tractor. (yep even redneck farmers have high tech toys)

You knew you were on the tractor and the sound was waaay in the background but Telegraph Road was completely enjoyable and it made the hot workday a little more enjoyable. I think Bose did a good job...not perfect..but what is?

[VolaveruntMercadal]

OMFGWTH you are a genius

[cito35th]

yup Cancelling sound waves

this is called resonance

[mao12345]

No, it's called intereference. Resonance is a completely different phenomenon.

[cito35th]

right

ima spam my self lol

[ipisac]

pretty cool

good job =]

[antoniocossio]

Something interesting to add is that BOSE noise cancelling just cancel what they consider noise, witch is repetitive sound patents. It works quiet well, in fact you hear more clearly. DeRr

[mao12345]

They try to cancel out all sound from the environment. HOWEVER, due to engineer and signal processing limitations, they're only successful at cancelling out low frequency sounds that's repetitive. Nonrepetitive, high frequency sounds are unpredictable and fundamentally difficult to cancel out--such as the voice of your annoying officemate.

[hyundaixl]

hmm... interesting!

[myurgil]

Apparently, YouTube doesn't support stereo sound.

[PLdrummer]

yes it does, not by default (yet). You should add to the video description to add &fmt=18 at the end of the video URL, that will bring up an MP4 video file with stereo sound. It is quite interesting, first (mono) sound, I heard nothing, but with stereo sound I heard the music, i don't think that's the effect that you were going for, but still worth noting. Try it yourself, just add &fmt=18 at the end of the video URL and click enter.