Tiny Tube for Hearing Aids (Feb, 1947)
This tube is about the same size as an entire modern hearing aid.
Tiny Tube for Hearing Aids
Only 3/4-inch long and 3/8-inch wide, tubes like this powered such war devices as walkie-talkies and mine detectors. Now their maker, Sonotone, is using them in hearing devices. Three of them go into Sonotone’s latest instrument, which can be used for either low- or high-powered amplification.