The voice of Alexander Graham Bell has been heard for the first time after the Smithsonian's National Museum of American History recovered the sound from a 130-year-old recording using an optical 3D scanning method.
As part of a collaborative project with the Library of Congress and Lawrence Berkeley National Laboratory, a wax-on-binder-board disc that carries the initials ‘AGB’ and dated 15 April 1885 was submitted to the non-invasive optical sound recovery process. The investigation was undertaken on Library of Congress equipment developed by the Berkeley Lab.
On the recording, Bell says ‘in witness whereof, hear my voice, Alexander Graham Bell’.
‘Identifying the voice of Alexander Graham Bell, the man who brought us everyone else’s voice, is a major moment in the study of history,’ said John Gray, director of the museum. ‘Not only will this discovery allow us to further identify recordings in our collection, it enriches what we know about the late 1800s – who spoke, what they said, how they said it – and this formative period for experimentation in sound.’
The optical technique used to scan and recover sounds was first conceived by Berkeley Lab in 2002 and jointly developed with assistance from the Library of Congress and other institutions over the past 11 years.
The groove shape of the disc is measured using precision optical metrology methods and digital image processing. A confocal microscope generates a 3D image of the surface of the disc. This is then analysed to emulate the motion of a stylus moving through the disc’s grooves, reproducing the audio content and producing a standard digital sound file. The image can also be processed to remove evidence of wear or damage, such as scratches and skips.
In addition to the identification of Bell, the museum has also identified the voice of Alexander Melville Bell, the famous inventor’s father. In a recording made September 1881 on a wax-coated drum, the elder Bell declaims: ‘There are more things in heaven and earth, Horatio, than are dreamt of in our philosophy. [Trill] I am a graphophone, and my mother was a phonograph.’ The younger Bell deposited this recording, and the machine on which it was recorded, at the Smithsonian in 1881 to be used as proof of precedence in case of a patent war. The positive identification of Alexander Melville Bell is corroborated by a 1937 recollection by Charles Sumner Tainter, a member of the Volta Laboratory Associates.
