What did Alexander Graham Bell’s voice sound like?

In his rivalry with Thomas Edison, Graham Bell made many attempts to record sound using media that ran the gamut from metal, glass, and foil to paper, plaster, and cardboard. Many of Bell's discs survive, but the technologies used to record them are long forgotten. Researchers and scientists from the National Museum of American History and the Library of Congress in Washington, the Lawrence Berkeley National Laboratory in California, and the University of Indiana have collaborated on a project to catalog and decipher the primative recordings, using high-resolution digital scans to convert them to audio files. One wax-and-cardboard disc, recorded...