Poor mans noise isolating ear-buds. Many advantages over ($200-$300)Bose: cheaper (pennies on the dollar) and smaller, allows mobility, no batteries required. Using existing (JVC) noise canceling Ear-buds, use Flents (or other manufacturers) spongy-type earplugs in place of the JVC plug. If you have heat-shrink, you can replace and elongate the JVC tube to allow inserting the Flent's plug better into your ear.
Great for planes, bus/car, mowing the grass, loud work environment, etc. Your mp3 player will only require 1/2 volume with these - thereby extending battery life.