Noise Canceling Headphones

The difference between passive and active reducing headphones is that passive is layers of foam. Active noise uses destructive sound waves to get block the noise. I think that is that interference because the music cancels out the outside sound.

http://www.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

Passive noise creates it to be harder to listen to music, noise canceling headphones get rid of this so you can listen to music in a lower tone.
Active headphones use destructive interference to take out the low frequency sounds. The computer sends out the same wave but waits after the first wave is sent. But waits a little while before sending the second wave.

Passive noise reduction blocks the sound from getting to your ears. Active noise reduction read the incoming noise and prevent the sound from coming in your ears. I think active noise reduction works by taking two noises and making it so by the time they reach your ears they cancel each other out so that you can't ear it.

http://www.ehow.com/about_5106048_passive-noise-reduction-headphones.html

Differences between active and passive headphones are that active headphones have a little computer in them that have a level that blocks high-frequency sound waves and another level that blocks lower-frequency sound waves. Where as passive headphones have foam that don't let any other noise through to your ears. The type of interference used is destructive interference. I think that the active headphones work by creating their own waves that are the opposite of the waves coming from the outside so it makes a destructive interference and no sound. http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

active head phones have a little computer .They make there own sound waves that sound like the sound waves coming in. they cancel out the other sounds so there is silence. Passive has aloute of layers densely packed together.

passive headphones, let some sound come in because thiers foam that is blocking some of the sound but not a lot it's nothing like the active headphones, cant hear anything because of the computer inside of it and its programed to were you cnat hear anything

Passive headphones use heavy and dense foam to block noise, the active headphones actually eliminate lower frequency sounds.

Active headphones use destructive interference to get rid of low frequency sounds.

The computer sends out the same wave but waits a little bit after the first wave is sent.

Passive blocks the noise from reaching your ears, and Active produces a sound to intercept and block the noise. A type of speaker and emits a sound wave that matches with the same amplitude. The interference effectively cancel each other out.
http://en.wikipedia.org/wiki/Active_noise_control

Passive headphones are foam that block out all sounds.Active you can hear a little of the outdoors. And active headphones are for activities outdoors so you can listen for things outside.

Active noise reducing headphones cancel unwanted noises by mimicking the outside sound. When the two sounds collide they cancel each other out, and the result is no sound at all. This is Destructive Interference. Passive noise reducing headphones block the sound out.

The active earphones have foam that keeps the sound out from the outside and the sound in from the ipod. The passive earphones are just controlled by a computer and they are just plastic earbuds. I think that the active earphones work better because of the foam. The foam keeps out the sound very well because there is so much of it. The sound waves from the outside bounce off the earphones. It is deconstructive inference because when the sound waves bounce off the earphones there is just silence. http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

Passive headphones only has foam covering your hear while a active headphone set as a computer in it. They actually create their own sound waves that copy the incoming noise in every respect except one. The headphones are 180 degrees out of phase with the incoming wave.

Passive earphones instantly keep sound from reaching your ear. Active noise reducing headphones make other noises to block out other noises. Passive ear phones are foam. The foam helps to block out sound and eliminates it. Active Earphones make sounds inside the earphones which eliminates other sounds outside of the head phones.

Passive headphones block out all sound by using foam to absorbe the sound. Active headphones reduce all sound and lower-frequency sounds. The headphones create a new sound wave that mimics the original sound. they use a destructive wave to block out all the sound. http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

Active headphone block ou sound by using a mirror of the sound. The passive headphones block out sound with foam.
Active:http://www.califone.com/blog/2010/02/26/active-vs-passive-noise-cancellation/
Passive:http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

Noise canceling headphones can use two different kinds of technology. Passive headphones can only use one kind of technology.Passive: They have phome to cancele it out. Active: They have a computer chip inside of it. The sound eaves are created by the sound of the music.
http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

The difference between passive and active is passive just uses foam active uses technology. Active noise reducing headphones work by canceling lower frequency by making there own sound waves that cancel sound waves made by other stuff which gives you silence.

Active noise control, aka sound field cancellation blocks out the sound of unwanted noises by using electro-acoustical means. To do this, the circuts within the headphone produces a sound that is a mirror-image of the disrupting sound. When the two sounds collide they cancel each other out, and then there is no sound at all. http://www.califone.com/blog/2010/02/26/active-vs-passive-noise-cancellation/

The active headphones copy the wave coming in but tweak it just a little. So it cancels the incoming sound out. The passive headphones have a lot of foam to block out sound. http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

The difference between active and noise reducing headphones is that the passive headphone don't block out all of the noises around you when the noise reducing headphones does. Active noise reducing headphones have special materials in them that block out sound waves from the your surroundings. They also have noise-filtering properties. They block out high frequencies. The active noise reducing headphones uses Destructive Interference. http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

Passive noise reducing headphones use layers of high-density foam to filter noise. Active noise reducing headphones use sound waves created by the headphone speaker to cancel out the noise. It uses deconstructive waves to cancel the noise. Link: http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

Passive Headphones try to block out sound with material. Active one create an equal sound and sends it back to cancel it out. Passive Headphones use Foam to "Block noise. Active Headphones use Sounds to "Cancel out" the background noise. The Active use Destructive interference and the Passive blocks it out. http://www.quietheadphones.com/faq/

passive only has foam. active noise reducing headphones have a sound wave that's going toward the sound that you don't want to hear. the interference that is at hand would be a destructive interference.
http://www.howstuffworks.com/enlarge-image.htm?terms=active+noise+reducing+headphones&page=1

Passive headphones just have a bunch a layers of foam to try and block noise. While active noise reducing headphones actually are creating white noise to go against the sound. Active noise reducing headphones work by first having layers of foam to block sound. And then it creates other noise to go against it which is called destructive interference. The destructive interference cancels out both sounds so there is no sounds at all.
http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

With the passive headphones the design simply blocks out the sound while the active ones send out waves deigned to block and eliminate all the outside sound using a destructive inference.
http://www.ehow.com/about_5106048_passive-noise-reduction-headphones.html