Now Hear This
Imagine eliminating all unwanted noise and only hearing the sounds you need to hear. That is the goal of noise-cancellation technology.
In the modern world, there is plenty of unwanted noise from jet aircraft engines, construction equipment, and factory machinery. Traditionally, the way to deal with noise has been to put a barrier, such as an ear plug or ear muffler, between the source of the noise and your ears. This type of ear protection has the drawback, however, that it blocks out most sound, not just unwanted noise. That makes communication with co-workers difficult. Now, new technology is available that selectively removes unwanted noise, but transmits the sounds you need to hear.