Picture yourself riding on a bus or train. With your favorite tunes all inside your ipod you get the urge to listen to them while on the commute. How would you want to shield your ears from hearing other sounds aside from your music? The easy solution is buying yourself noise canceling earbuds. It might seem unbelievable at first sight especially when observing how small these gadgets are but believe it or not these things do what they are supposed to do. They are also known as “Etymotic” earphones, which is Greek means “true to the ear”.
We may ask, how do these earbuds perform the task of noise reduction? Inventors say there are two ways to reduce noise, one “Passive” and the other “Active”. Passive noise reduction, which is the simpler of the two, is made possible when the earbuds are designed so that they fit snugly into the ears. The effect is that no sound escapes outside and neither does any sound get in. These earbuds have large pieces of high density foam built around them so that one wears them by fitting the foam so that it acts like a perfect seal within your ear canal. They also are equipped with plastic reusable earpieces similar to the ear plugs swimmers usually use. This is the principle behind passive noise reduction. However, passive noise reduction have some limitations and so that’s where active noise reduction comes in. Active noise reduction is much more complex and employs a more advanced technology that’s why it’s the type used in the sophisticated noise-cancelling headphones many pilots wear. These headphones have a small microphone built into their case that continuously checks the background noise and transmits it to an electronic circuit inside the headphone case. Now get this, the circuit produces an “anti-sound” that “inverts” the noise so that unpleasant sound is erased by destructive interference diminishing considerably what you would normally hear. The result is that what you get is near total silence, perfect to hear that favorite music of yours.