Sony MDRNC7 Noise Canceling On-Ear Headphones for $18.84.  Here is a screenshot for your reference.  It features Aactive noise canceling headphones that supposedly reduces outside ambient noise by 87.4% and can be switched on/off. It also includes an airplane adapter for in-flight entertainment.  As a comparison, Best Buy currently has this set of Sony noise-cancelling headphones for [...]