Headphones are a pair of small loudspeakers, or less commonly a single speaker, which are held close to the user’s ear. Headphones are often referred to as cans but may also be known as earbuds or headsets.
Headphones were first used around 1919 were initially used for radio work. Early headphones often used moving iron drivers, either single ended or balanced armature. They also offer very poor comfort and comfort and fit compared to modern headphones which are designed to a series of purposes including general use or for sports reacreation.
Early headphones also came with bare electrical connections which meant that users could be shocked if they touched the bare headphone connections while adjusting an uncomfortable headset.
The earcup of a headphone will be either open or closed. Open headphones use an open grille on the back of the earcup, enabling sound waves to propagate away from the ear freely. This form of backing does not isolate the listener from outside sound and ambience. The sound generated by this form of headphone can also he heard by other people within the local area. Sealed chamber headphones are often claimed to have the negative effect of distorting sound quality and earphone performance in certain frequencies, however bass frequencies are stronger in a sealed chamber headphone design.
Sports headphones refer to lightweight models with two general headband styles: standard vertical bands that arch over the head or horizontal designs that extend behind the head or neck. These headphones are commonly open-backed designs which sport for jogging and other sports activities by allowing ambient street level noise in.
Because of their size and their acoustic isolation, full-size headphones are often considered to be better suited to home use rather than as a portable option.
Earbuds often come free with MP3 players and portable CD players. The earpieces rest on the outer ear or need to be inserted into the ear canal. Some models also include ear clips for a more secure fit.