Brownie crystal radio receiver and pair of BTH headphones, mid 1920s.For many early radio listeners, purchasing a receiver which came with a loudspeak... - SuperStock
Play It Green | Sustainable Headphones: Go Green with Your Tunes
Antique Headset, 1920s - Etsy UK
Vintage German Omega 2000 headphones probably 1920's - OD&D
HEADPHONES, 5 pairs, 1920s/30s, among others LM Ericsson. Miscellaneous - Modern consumer electronics - Auctionet
1920's(ish) LITTLE TATTLER radio headphones | Collectors Weekly
Retrofitting Vintage 1920's Headphones With Modern Sound : 7 Steps (with Pictures) - Instructables