Noise blocking headphones insulate your ear from outside sounds to reduce the amount of outside noise allowing you to better hear and focus on the sounds from the headphones.
Noise cancellation headphones work by blocking high-frequency sound waves and erasing lower-frequency sound waves. This can occur due to their ability to mimic incoming noise in order to produce their own sound waves.
If you get real Bose headphones, yes they do have noise cancellation. It's pretty great. They do have knock off Bose headphones called Brose but they don't work as well as Bose.
The Bose QuietComfort 2s are the best I've tried...but they're pretty expensive.
The headphones that are rated the highest for noise cancellation are Bose headphones. They are recommended for long flights and for times when you will want to cancel out outside noise.
Any unwanted noise is muted with the noise cancelling headphones. For example if there is a baby on the plane that is crying. The headphones will mix the noise from your music/media and the external noise and cancels out the external noises.
According to an article on technology website CNET, where several noise-cancelling headphones were compared, the headphones with the best rating were the PSB Speakers M4U 2 Active Noise Cancelling Headphones.
Usually, you can't add active noise cancelling to existing headphones. Noise-cencelling headphones have a built-in microphone that listens to the sound around the headphones so that the electronics can cancel the noise.
There are many places where one can get Sennheiser noise canceling headphones. One can get Sennheiser noise canceling headphones at popular on the web sources such as Best Buy and Target.
http://reviews.cnet.com/best-noise-cancelling-headphones/ This site includes different brands of noise cancelling headphones. Local electronics stores may hold them in stock.
Noise reduction headphones are rated based on decibel readings. The decibel scale is logarithmic. A change of 10 dB means a tenfold change in loudness. Noise reducing headphones can block out 40 dB of ambient noise.
According to an article on technology website CNET, where several noise-cancelling headphones were compared, the headphones with the best rating were the PSB Speakers M4U 2 Active Noise Cancelling Headphones.
Sennheiser HD 515 headphones don't have true noise cancellation so that they do allow in outside noise.