In 1949 the American Merri-Lei Corporation of Brooklyn, NY debuted a radio receiver embedded in a womens hat. Thsi was a fairly heavy decive. It was a 2-tube single-loop battery device with a 1S5 tube and a 3V4 tube connected as an "Ultraaudion". The loop antenna is mounted in such a way that it can be rotated for best reception. Just try to sit still. Thetuning knob is mounted between the two tubes. The ear phones are built-in. The powersource are two batteries, a1.5 and a 22.5 volt batterie that are to be carried in the coat pocket and connected with the "Radio-Hat" by a short lead. It's semi-portable by todays standards, the hat weighed 12 oz and the power supply 7-oz.It was advertised in Popular Science among other periodicals of the day. It was an invention of Victor T. Hoeflich. It only cost $7.95 each. More here, and here. The tradition lives on here, among other places.
As absurd as the device seems it caused enough of a stir that Zenith saw fit to produce their own version to compete in 1952. Their take on the device housed parts of the device in a walking cane to distribute the weight. That’s here with a short documentary.
By the 1960s there were far lighter versions built into visors, some were even solar powered. I think Solar Vision still makes this one. Now of course it costs $26.50 plus $6.50 for shipping. Oh, the pains of inflation.