Noise-isolating earbuds are listening devices commonly used with portable media players to allow a person to hear the audio from the player. These earbuds are specifically designed to help reduce the amount of ambient noise that may otherwise be heard by a listener to improve the general listening experience. They are typically constructed from plastic, though some also use foam pads to improve comfort when placed in the ear canal. Noise-isolating earbuds can be quite effective at eliminating constant, ambient noise, though they are typically less effective in reducing or eliminating sudden and intermittent noises.
Most noise-isolating earbuds are designed as two separate listening devices connected by a single wire inserted into a media player or similar device. Unlike headphones that are connected together and go over the ears of the listener, earbuds are typically designed to insert just inside of the ear canal of the listener and each bud is not directly connected to the other one. This can allow earbuds to be more easily worn in situations in which headphones may be impractical, such as during exercise. Since noise-isolating earbuds are inserted into the ear canal, the audio signal usually comes through quite well, though some people may find them uncomfortable when worn for long periods of time.
Noise-isolating earbuds typically function by fitting snug within the ear canal, which reduces the amount of ambient sound that can also enter the ear canal. This means that the effective noise-isolation of such earbuds relies on how well they fit into the ear of the wearer. More effective earbuds often fit slightly deeper within the ear canal, and are typically shaped to fit comfortably within the ear canal. Noise-isolating earbuds are usually effective in reducing noise that is constant, such as the sound of the engines on an airplane, but are not as effective for eliminating sudden sounds such as yelling or thunder.
Some noise-isolating earbuds are also designed with noise-canceling features that are more effective for dealing with sudden or intermittent sounds. Noise-canceling features utilize a microprocessor within the earbuds that analyze sudden incoming sounds, such as yelling or hand clapping. The microprocessor analyzes the sound waves from those sounds, and then generates inverse waves equal to those produced by the external noise. These inverted sound waves are then played along with the audio from the media player, canceling out the external noise and allowing the listener to hear only his or her audio selection.