First Electric Hearing Aid (1 янв 1898 г. – 1 дек 1898 г.)
Описание:
Miller Reese Hutchison creates the first electric hearing aid called the akouphone. It used a carbon transmitter in order to make the device portable. This hearing aid would amplify weak signals into strong signals using electrical currents.Добавлено на ленту времени:
Дата:
1 янв 1898 г.
1 дек 1898 г.
~ 11 months