The earliest wiretaps were extra wires —“ connected to the line between the telephone company ’ s central office and the subscriber — that carried the signal to a pair of earphones and a recorder.

The operator dragged the wire across the crystal surface until a radio station or " static " sounds were heard in the earphones.

In early homebuilt sets, the earphones were the most costly component.

The coherer's electrodes were also attached to a DC circuit powered by a battery that created a " click " sound in earphones or a telegraph sounder, or a mark on a paper tape, to record the signal.

When extra metal plates were added to cover the earphones, the result was the M3.

" In Ear " headphones or earphones using balanced armature technology were launched in November 2007.

The inMotion 716 and 616 looked and performed much like their Etymotic cousins but were marketed toward the average listener looking to replace their free bundled portable earbuds with higher-performance earphones.

Batman's designs range widely in the pages that are included, some modifications that were speculated included: chin guards with built-in radio and microphone, earphones built into the cowl, pouches and compartments on the boots, gauntlet and belt ; wing-like capes with shoulder protrusions ( which could have obstructed vision and snag in tight spaces ); capes that were perfect simulations of bat wings, but would prove too heavy, variation in the length of ears, colors, designs that looked too " fancy ", too " gimmicky ", too " Mysterioso " ( which was entirely red ), too " weird " and too demonic.

Originally included as a component of the company's personal monitor systems, Shure's earphones became an independent product after Shure realized that users were re-purposing the in-ear monitors for music listening on portable audio devices such as MP3 players.

In 2006, Shure's E4c earphones were awarded a TEC Award from the Mix Foundation for Excellence in Audio for outstanding technical achievement.

Attached to the frame were pigskin gloves, rubber boots, and an aluminum and plastic helmet with a removable faceplate that could accommodate earphones and a throat microphone.

Some ear defenders employ active sound protection, in which a microphone mounted in the headset picks up ambient sounds and transmits them through a dynamic range compression circuit to earphones inside.

The spark at the buzzer's electrical contacts served as a weak radio transmitter, so when the detector began working the buzz could be heard in the earphones, and the buzzer was then turned off.

She goes to tell Father Adamsky this, but has a breakdown while telling him ; Sonny becomes more sinister and like a demon, as his face starts turning into a demon like face, startled he tries to keep his family away, but is unsuccessful due to the possession by the demon, who usually contacts Sonny through his earphones.

Sometimes a distinction is made between a portable player, battery-powered and with one or more small loudspeakers, and a personal player, listened to with earphones.

As the popularity of portable music listening devices increased, Shure recognized the earphones from their personal monitoring packages being used for recreational listening, and later made versions of their sound-isolating earphones available for purchase separately specifically for that market.

Marshall Amplification is a British company that designs and manufactures music amplifiers, brands personal headphones / earphones ( made by Zound Industries ), and, having acquired Natal Drums, drums and bongos.

Used by Laura and David on Grenada in conjunction with custom made earphones.

Sensory evoked potentials ( SEP ) are recorded from the central nervous system following stimulation of sense organs ( for example, visual evoked potentials elicited by a flashing light or changing pattern on a monitor ; auditory evoked potentials by a click or tone stimulus presented through earphones ) or by tactile or somatosensory evoked potential ( SSEP ) elicited by tactile or electrical stimulation of a sensory or mixed nerve in the periphery.

The low power produced by crystal radios is insufficient to power an unamplified loudspeaker so earphones are used.

This is typically achieved by recording the signals of the microphones and earphones of the pilots headsets and of an area microphone in the roof of the cockpit.

To detect the voltage pulse produced by the coincidence circuit when a coincidence event occurred, Rossi first used earphones and counted the ‘ clicks ’, and soon an electro-mechanical register to count the coincidence pulses automatically.

The psychic telephone was an instrument invented by F. R. Melton of Nottingham, UK, consisting of a box containing a rubber bag connected with a pair of earphones from a wireless set.

The film refers to an audio recording of the fatal attack captured by Treadwell's video camera, and although Herzog is shown listening to it on earphones clearly disturbed, it is not played in the film.

Earbuds and earphones refer to very small headphones that are fitted directly in the outer ear, facing but not inserted in the ear canal ; they have no band or other arrangement to fit over the head.

Other brands include IWANTIT, an audio brand making electrical appliances such as earphones, radios and chargers ; Advent, a computer brand which makes electrical appliances such as notebooks, desktop PCs and tablet PCs ; Sandstrøm, used on higher-class electrical items, including vision products, MDA, SKA and other CE items.

Altec Lansing later discontinued signing contracts with other companies, and instead introduced their earphones in 2008.

In NASA spacesuits, communications are provided via a cap worn over the head, which includes earphones and a microphone.

By adjusting the local oscillator frequency correctly, the beat frequency is in the audio range, and can be heard as a tone in the receiver's earphones whenever the transmitter signal is present.

In 1899, a projected sound-film system known as Cinemacrophonograph or Phonorama, based primarily on the work of Swiss-born inventor François Dussaud, was exhibited in Paris ; similar to the Kinetophone, the system required individual use of earphones.

In one scene, she appears to have a hairstyle similar to Princess Leia in Star Wars, but it is revealed that she is actually wearing a pair of earphones.

In-ear earphones, whose sound enters directly into the ear canal without any opportunity to be deflected or absorbed elsewhere, are a common cause of tinnitus when volume is set beyond moderate levels.

It then amplifies changes in the signal voltage to drive a loudspeaker or earphones.

It is common to see Japanese commuters riding the train to work, enjoying their favorite manga, or listening through earphones to the latest in popular music on portable music players.

He is wearing huge earphones, rather than a small radio, and big glasses meant to blind him and give him headaches.

In order to eliminate any " unfair advantages ", the Handicapper General forces him to wear the most extreme handicaps: not only the small mental handicap radios to interfere with any intelligent thoughts, but also huge earphones and spectacles intended to make him half blind and give him tremendous headaches.

The in-ear versions are known as earphones or earbuds.

) The outer-ear earphones are portable and convenient, but many people consider them to be uncomfortable and prone to falling out.

The company's first radio was named " Tommeliten ", and used only earphones.

Commonly shoplifted items are usually small and easy to hide, such as groceries, especially steak and instant coffee, razor blades and cartridges, small technology items such as iPods, smartphones, USB flash drives, earphones, CDs and DVDs, cosmetics, jewelry, vitamins, pregnancy tests, electric toothbrushes and clothing.

Crystal radios are the simplest type of radio receiver and can be handmade with a few inexpensive parts, like an antenna wire, tuning coil of copper wire, crystal detector and earphones.

Thus crystal sets produce rather weak sound and must be listened to with sensitive earphones, and can only pick up stations within a limited range.

The rectified current from the detector still had radio frequency pulses from the carrier in it, which did not pass well through the high inductance of the earphones.

The requirements for earphones used in crystal sets are different from earphones used with modern audio equipment.