earpiece vs earplug

earpiece

noun
  • A speaker placed inside or held near to the ear. 

  • The arm on a pair of glasses that hooks over the ear to hold them in place. 

  • A receiver of a telephone to hold near to one's ear. 

earplug

noun
  • A piece of protective gear meant to be inserted in the ear canal to protect the wearer's hearing from loud noises or the intrusion of water. 

verb
  • To fit with earplugs. 

How often have the words earpiece and earplug occurred in a corpus of books? (source: Google Ngram Viewer )