HEAD PHONE TECHNOLOGY
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears.
Headphones are also known as earspeakers, earphones. Circumaural 'around the ear' and supra-aural 'over the ear' headphones use a band over the top of the head to hold the speakers in place. Another known as earbuds or earpieces. Other are bone conduction headphones, which typically wrap around the back of the head and rest in front of the ear canal, leaving the ear canal open.Headphones connect to such as an audio amplifier, radio, CD player, portable media player, mobile phone, video game console, or electronic musical instrument,either directly using a cord, or using wireless technology such as Bluetooth.
The first headphones were developed in the late 19th century. Headphones may be used with stationary CD and DVD players, home theater, personal computers, or portable devices e.g., digital audio player/MP3 player, mobile phone, as long as these devices are equipped with a headphone jack. Cordless headphones are not connected to their source by a cable. Headsets designed for telephone use typically cannot reproduce sound with the high fidelity of expensive units designed for music listening by audiophiles. Headphones that use cables typically have either a 1/4 inch (6.35mm) or 1/8 inch (3.5mm) phone jack for plugging the headphones into the audio
Headphones are available with high or low impedance (typically measured at 1 kHz). Low-impedance headphones are in the range 16 to 32 ohms and high-impedance headphones are about 100-600 ohms. In recent years, impedance of newer headphones has generally decreased to accommodate lower
Headphones with soldered headphone jack cables. Wireless on-ear headphones. Often has an inbuilt headphone jack. Wireless over-ear headphones. Often has an inbuilt headphone jack. ireless earphones
A headset is a headphone combined with a microphone. Headsets provide the equivalent functionality of a telephone handset with hands-free operation. Among applications for headsets, besides telephone
use, are aviation, theatre or television studio intercom systems, and console or PC gaming. Telephone headsets connect to a fixed-line telephone system. A telephone headset functions by replacing the handset of a telephone. For older models of telephones, the headset microphone impedance is different from that of the original handset, requiring a telephone amplifier for the telephone headset. A telephone amplifier provides basic pin-alignment similar to a telephone headset adaptor, but it also offers sound amplification for the microphone as well as the loudspeakers. Communication headsets are used for two-way communication and typically consist of a headphone and attached microphone. Such headsets are used in a variety of professions as aviation, military, sports, music, and many service-oriented sectors.
Headphones use various types of transducer to convert electrical signals to sound. The moving coil driver, more commonly referred to as a "dynamic" driver is the most common type used in headphones. It consists of a stationary magnet element affixed to the frame of the headphone. Electrostatic drivers