earphone(n = noun.artifact) earpiece, headphone, phone - 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"
is a kind of electro-acoustic transducer
has particulars: earplug, receiver, telephone receiver

earphone, n. a device applied to the ear to aid hearing or receive radio or telephone communications.