First Concept of the Hearing Aid (1 янв 1600 г. – 1 янв 1700 г.)
Описание:
Jean Leurechon makes the first device to help people with Deafness and hard of hearing (no exact date of invention, just first seen in the 17th century). The first hearing aid was an "ear trumpet". People would place ir in the ear and the other person would talk into it and sound would be amplified.Добавлено на ленту времени:
Дата:
1 янв 1600 г.
1 янв 1700 г.
~ 100 years