Headphones are a pair of small loudspeakers, or less commonly a single speaker, with a way of holding them close to a user's ears and a means of connecting them to a signal source such as an audio amplifier, radio or CD player. They are also known as earphones, earbuds, stereophones, headsets or, informally cans. In the context of telecommunication, the term headset is used to describe a combination of headphone and microphone used for two-way communication, for example with a telephone.
History
Old telephone earpiece
The telephone earpiece such as the one pictured at the right was common around the turn of the 20th century. From the earpiece developed the headphones. Sensitive headphones were the only way to listen to audio signals before amplifiers were developed.
Brandes radio headphones, circa 1920
Very sensitive headphones such as those manufactured by Brandes around 1919 were commonly used for early radio work. These early headphones used moving iron drivers, either single ended or balanced armature. The requirement for high sensitivity meant no damping was used, thus the sound quality was crude. They also had very poor comfort compared to modern types, usually having no padding and too often having excessive clamping force to the head. Impedance varied, but 1,000 to 2,000 ohms was common, which suited both triodes and crystal sets.
When used with early powered radios, the headphone was normally connected to the positive high voltage battery terminal, and the other battery terminal was securely earthed. The use of bare electrical connections meant that users could be shocked if they touched the bare headphone connections while adjusting an uncomfortable headset.
Old telephone earpiece
The telephone earpiece such as the one pictured at the right was common around the turn of the 20th century. From the earpiece developed the headphones. Sensitive headphones were the only way to listen to audio signals before amplifiers were developed.
Brandes radio headphones, circa 1920
Very sensitive headphones such as those manufactured by Brandes around 1919 were commonly used for early radio work. These early headphones used moving iron drivers, either single ended or balanced armature. The requirement for high sensitivity meant no damping was used, thus the sound quality was crude. They also had very poor comfort compared to modern types, usually having no padding and too often having excessive clamping force to the head. Impedance varied, but 1,000 to 2,000 ohms was common, which suited both triodes and crystal sets.
When used with early powered radios, the headphone was normally connected to the positive high voltage battery terminal, and the other battery terminal was securely earthed. The use of bare electrical connections meant that users could be shocked if they touched the bare headphone connections while adjusting an uncomfortable headset.
Applications
Headphones can be used both with fixed equipment such as CD or DVD players, home theater, personal computers and with portable devices (e.g. digital audio player/mp3 player, mobile phone, etc.). Cordless headphones do not need to be connected via a wire, receiving a radio or infrared signal encoded using a radio or infrared transmission link, like FM, Bluetooth or Wi-Fi. These are actually made of powered receiver systems of which the headphone is only a component, these types of cordless headphones are being used more frequently with events such as a silent disco or Silent Gig.
Headphones are widely used for listening to audio sources for recreation. In the professional audio sector headphones are used in live situations by disc jockeys with a DJ mixer and sound engineers for monitoring signal sources. In radio studios, DJs use a pair of headphones when talking to the microphone while the speakers are turned off, to eliminate acoustic feedback and monitor their own voice. In studio recordings, musicians and singers use headphones to play along to a backing track. In the military, audio signals of many varieties are monitored using headphones.
Wired headphones are attached to an audio source. The most common connectors are 1/4" and 3.5 mm stereophonic jack plugs and sockets. The older 1/4" standard is used on professional equipment, and is often used on fixed equipment. Sony introduced the smaller, cheaper, and now widely-used, 3.5 mm "mini" stereo connector in 1979, adapting the older monophonic 3.5 mm connector for use with its Walkman portable stereo tape player. Adapters are available for converting between 1/4" and 3.5 mm devices.
Headphones can be used both with fixed equipment such as CD or DVD players, home theater, personal computers and with portable devices (e.g. digital audio player/mp3 player, mobile phone, etc.). Cordless headphones do not need to be connected via a wire, receiving a radio or infrared signal encoded using a radio or infrared transmission link, like FM, Bluetooth or Wi-Fi. These are actually made of powered receiver systems of which the headphone is only a component, these types of cordless headphones are being used more frequently with events such as a silent disco or Silent Gig.
Headphones are widely used for listening to audio sources for recreation. In the professional audio sector headphones are used in live situations by disc jockeys with a DJ mixer and sound engineers for monitoring signal sources. In radio studios, DJs use a pair of headphones when talking to the microphone while the speakers are turned off, to eliminate acoustic feedback and monitor their own voice. In studio recordings, musicians and singers use headphones to play along to a backing track. In the military, audio signals of many varieties are monitored using headphones.
Wired headphones are attached to an audio source. The most common connectors are 1/4" and 3.5 mm stereophonic jack plugs and sockets. The older 1/4" standard is used on professional equipment, and is often used on fixed equipment. Sony introduced the smaller, cheaper, and now widely-used, 3.5 mm "mini" stereo connector in 1979, adapting the older monophonic 3.5 mm connector for use with its Walkman portable stereo tape player. Adapters are available for converting between 1/4" and 3.5 mm devices.
Types of headphones
There are many different types of headphone designs, with the listening situation and the needs of the listener determining what type of headphone will be used. Generally, headphone formfactors can be divided into four separate categories: circumaural, supra-aural, earbud, and in-ear.
There are many different types of headphone designs, with the listening situation and the needs of the listener determining what type of headphone will be used. Generally, headphone formfactors can be divided into four separate categories: circumaural, supra-aural, earbud, and in-ear.
Earcup headphones
Earcup or on-ear headphones rest on the exterior of the ear and were the earliest headphone form designed.
The housing, or earcup, of an earcup headphone will be either open or closed. Open headphones, sometimes marketed as “open air” headphones, have an open grille on the back of the earcup, exposing the driver to the outside and allowing sound waves to propagate away from the ear freely. This backing type does not isolate the listener from outside sounds; in addition, sound through open headphones can be heard by others in the vicinity of the user. They usually have less distortion due to the lack of earcup resonance. Closed headphones have a sealed backing, which attenuates sound waves propagating away from the ear. As a result, listeners away from the headphones cannot hear the produced sound easily. In addition, sound from outside is attenuated by the sealed backing, providing a level of isolation to the listener. A sealed chamber is often claimed to have the negative effect of distorting sound in certain frequencies due to resonances within the earcup housing, however, bass frequencies are stronger in a sealed chamber headphone design.
Earcup or on-ear headphones rest on the exterior of the ear and were the earliest headphone form designed.
The housing, or earcup, of an earcup headphone will be either open or closed. Open headphones, sometimes marketed as “open air” headphones, have an open grille on the back of the earcup, exposing the driver to the outside and allowing sound waves to propagate away from the ear freely. This backing type does not isolate the listener from outside sounds; in addition, sound through open headphones can be heard by others in the vicinity of the user. They usually have less distortion due to the lack of earcup resonance. Closed headphones have a sealed backing, which attenuates sound waves propagating away from the ear. As a result, listeners away from the headphones cannot hear the produced sound easily. In addition, sound from outside is attenuated by the sealed backing, providing a level of isolation to the listener. A sealed chamber is often claimed to have the negative effect of distorting sound in certain frequencies due to resonances within the earcup housing, however, bass frequencies are stronger in a sealed chamber headphone design.
Circumaural
Circumaural headphones (sometimes called fullsized headphones) have circular or
ellipsoid earpads that completely surround around the ears. This type of headphone is commonly used in recording studios and among audio enthusiasts.
Circumaural headphones (sometimes called fullsized headphones) have circular or
ellipsoid earpads that completely surround around the ears. This type of headphone is commonly used in recording studios and among audio enthusiasts.Supra-aural
Supra-aural headphones have pads that sit on top of the ears, rather than around them. They were commonly bundled with personal stereos during the 1980s.
Supra-aural headphones have pads that sit on top of the ears, rather than around them. They were commonly bundled with personal stereos during the 1980s.
Earbuds
Earbuds or earphones, such as these that ship with the Apple's iPod, rest in the outer part of the ear canal.
Canalphones extend into the ear canal, facilitating greater dynamic range than earbuds as well as isolation from outside noise.
Earbuds or earphones are headphones of a smaller size that are placed directly outside of the ear canal, but without fully enveloping it. They are generally inexpensive and are favored for their portability and convenience. However, due to their inability to provide isolation, they are not capable of delivering the same dynamic range offered by many full-sized headphones and canalphones for a given volume level. As a result, they are often used at higher volumes in order to drown out noise from the user's surroundings, which increases the risk of hearing-loss.During the 1990s and 2000s, earbuds became a common type bundled with personal music devices.
Earbuds or earphones, such as these that ship with the Apple's iPod, rest in the outer part of the ear canal.
Canalphones extend into the ear canal, facilitating greater dynamic range than earbuds as well as isolation from outside noise.
Earbuds or earphones are headphones of a smaller size that are placed directly outside of the ear canal, but without fully enveloping it. They are generally inexpensive and are favored for their portability and convenience. However, due to their inability to provide isolation, they are not capable of delivering the same dynamic range offered by many full-sized headphones and canalphones for a given volume level. As a result, they are often used at higher volumes in order to drown out noise from the user's surroundings, which increases the risk of hearing-loss.During the 1990s and 2000s, earbuds became a common type bundled with personal music devices.
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