Symbol 5077 from IEC 60417 - Title/Meaning: Headphones Function/description: To identify the socket, terminals or switch for headphones.
Additional information: 
Published in: First edition, 1973
Own work using: iso.org/obp/graphics/grs/3b72179a-222b-4ea7-b5d7-46c052766fed 200.png
Vectorization:  Mrmw