head·phone /ˈhɛdˌfon/
  戴在頭上的收話器,雙耳式耳機
  headphone
  耳機
  headphone
       n : 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" [syn: earphone, earpiece, phone]