Exam (elaborations)
ILE Exam Hearing Aids
- Course
- Institution
ILE Exam Hearing Aids Hand Cupped Behind Ear - ANSWER--first Hearing Aid -increased sound by 5-8db -included horns,trumpets, speaking tubes 1892 - ANSWER--carbon amplifiers patent by Alexander Bell -marketed until 1930;first patent for a telephone type hearing instrument 1920 - ANSWER-...
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