The comic page in question.
Sam Wilson appears to be listening to his TV through some earbuds because the noise upsets his falcon Redwing. He even looks kind of like he's adjusting the volume with his thumb. Most of the stuff I see online references the 1980s as the big boom for headphones of all sorts popping up. Were earbuds or something similar available in 1970? Could normal TVs be hooked to them?
Hope this is an appropriate place to ask about this!
*Edit: The image is from Captain America 132, in case anyone was wondering.
Such ivory-colored monaural earphones would have been familiar to any teen or young adult at the time, as they were utterly ubiquitous in the era of the transistor radio.
Small piezoelectric earpieces were developed in the 1920s, and were necessary for listening to the extremely small outputs produced by crystal radios. The devices were widely used on World War II electronics, requiring a minimum of power and letting only the wearer hear the output. For the same reason, portable radios even in the tube era usually included an earphone jack. Certainly the transistor radios developed in the 1950s all did. While Annette rocking out on the beach wouldn’t have used an earphone, her brother surreptitiously listening to the ballgame while working at the burger stand often had one of these white earpieces threaded inside his shirt to reach one ear.
By the late 1960s, a wide variety of audio devices, from portable tape recorders to small television sets, included earphone jacks, for plugging in what were known at the time as 1/8-inch mini-phone plugs (we now describe them as 3.5mm plugs). The sound quality . . . well, it was acceptable for AM radio. Serious headphones, as used by audiophiles with their hi-fi sets, came with 1/4-inch stereo phone plugs. The Sony Walkman in the 1980s used a stereo version of the 3.5mm plug for the lightweight headsets it came with and the cheap, tinny "earplug" faded away along with Top 40 AM radio.