This folder contains correspondence relating to Edison's deafness and to devices for the hearing impaired. Included are requests for Edison's opinion of existing hearing aids, as well as inquiries concerning his plans to invent such a device. Most of the letters received no answer or a standard reply stating that Edison had discontinued his hearing aid experiments and that he expected to return to them in the future. The correspondents for 1911 include Joseph Byrne of New York, a physician studying the functions of the inner ear and its relationship to sea sickness.
A sample of less than 5 percent of the documents has been selected. Most of the selected items contain marginalia by Edison. Courtesy of Thomas Edison National Historical Park.