It seems that the man who brought us the telephone, Alexander Graham Bell, has also left us with a recording of his voice. The historic lost audio file was found 128 years later by several researches around the nation using a technique that was developed at the Lawrence Berkeley National Laboratory. The Berkeley method was based on particle physics equipment, and relies on taking high-resolution digital images of the surface of a physical audio recording medium, like Bell’s wax disc. It then runs an analysis to rebuild the areas of the recording that are damaged, resulting in the playback of the recording.
In the recoding, you can hear Bell saying, “In the witness whereof, hear my voice, Alexander Graham Bell.” The audio recording was actually made on an old experimental wad disk that bell donated to the Smithsonian Institution’s collection. However, it was considered “unplayable” due to its antiquated technology and the researchers weren’t sure that it would play back or if it was in good condition.