Definitions:

1. A small audio device designed to be placed inside or over the outer part of the ear to deliver sound directly to the listener. NOUN
   • He used his earphones to listen to music while jogging.
2. Electro-acoustic transducer for converting electric signals into sounds, held over or inserted into the ear. NOUN
   • I wear earphones to listen to music on the subway.
   • Wireless earphones have become popular for their convenience and portability.

Synonyms:

• earbuds
• earpiece
• headphone
• in-ear headphones