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The Vacuum Tube Age of Hearing Aids (1 Jan 1920 Jahr – 1 Jan 1949 Jahr)

Beschreibung:

Earl C. Hanson invented the vacuum tube hearing aid and named it the vactuphone. Was one of the first hearing aids that a person could wear around the ear. Technology for amplification was better than previous hearing aids, though this hearing aid required two batteries making the cost greater.

Zugefügt zum Band der Zeit:

A Brief History of the Hearing Aid

ByBrenda Perez
28 Okt 2019
0
0
195

Datum:

1 Jan 1920 Jahr
1 Jan 1949 Jahr
~ 29 years

Abbildungen:

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