earphone

[n] - electro-acoustic transducer for converting electric signals into sounds
Found on http://www.webdictionary.co.uk/definition.php?query=earphone

earphone

earpiece noun electro-acoustic transducer for converting electric signals into sounds; it is held over or inserted into the ear; `it was not the typing but the earphones that she disliked`
Found on https://www.encyclo.co.uk/local/20974

earphone

small loudspeaker held or worn close to the listener`s ear or within the outer ear. Common forms include the hand-held telephone receiver; the ...
Found on http://www.britannica.com/eb/a-z/e/2

earphone

earphone Any device that converts electrical energy into sound waves and is worn over or inserted into the auditory opening; such as the ear.
Found on http://www.wordinfo.info/words/index/info/view_unit/2737/4

earphone

electroacoustic transducer by which acoustic oscillations are obtained from electric signals and intended to be closely coupled acoustically to the ear
Found on http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=801-27-18
No exact match found