Green’s Dictionary of Slang

head/earphones.

1913		Wireless World May v: [advert] High resistance ’phones.
1926		R. Macaulay Letter to Sister (1964) 27: No longer [...] does the husband have to sit in the evenings and listen to inanities from his wife [...]; he and she can now both sit in silence, with the phones on their ears.
1948		Electronics Aug. 88/2: A person listening to sound through a binaural system has the illusion that the sound originates in the room rather than in the phones.
1962		A. Nisbett Technique Sound Studio 256: Some degree of control of volume can be achieved with telephone receiver type phones by moving them a little off the ear.
1970		J. Earl Tuners and Amplifiers iii 76: It also pays for the amplifier etc. to carry a loudspeaker switch to cut the speakers when listening on ’phones.
1977		Rolling Stone 24 Mar. 79/2: Played back over the phones part of the system [...] the sense of space and realism of sound is unbelievable.
1990		W.D. Myers Mouse Rap 61: [H]e got his earphones stuck into his headbone and he’s steady pumping boom box. Then he scopes the dopes, debones the phones, and stands up.