I recently came across this online hearing aid museum. It is a very interesting and informative site. I think it is fascinating to see how hearing devices evolved over the years.
Did you know that the first electrical hearing aids appeared during the 20th century, thanks to the invention of the carbon microphone?
More at aid-museum.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+EhWhatHuh+%28Eh%3F+What%3F+Huh%3F%29