New Optical Scan Results from the Smithsonian Volta Laboratory Collection

Updated April 23, 2013


Optical scanning is a process to restore historic sound recordings, non-invasively.? The technology used here was developed mainly by a collaboration of Lawrence Berkeley National Laboratory and the Library of Congress.


The Smithsonian Institution National Museum of American History (SI NMAH) Volta Laboratory collection consists of early experimental sound recordings (1881-1886) created by Alexander Graham Bell, Charles Sumner Tainter, Chichester A. Bell, and associates.? In collaboration with the Smithsonian some of these recordings are being restored and presented to the public.? The present set includes Bell?s own voice.


In December of 2011 a first release of restored recordings from the SI NMAH Volta Laboratory collection was made.? See volta-release.html


Some general references

?        This is the general website for the IRENE/3D optical scanning projects??

?        This is a report about 3D optical scanning 3D-Scanning.pdf

?        This is a general report on the optical scanning development project Sound-Project-0311.pdf

?        Some simple details on optical scanning are given here


The files posted here are provisional. If referred to as FILTERED,? low pass filter has been applied.? The basic goal was clarity.


Some specific references

Smithsonian\Audio\Pages from Science 1888.pdf? This is a report in Science of a presentation made at the time concerning the Volta Lab research on sound recording.

Scholar Patrick Feaster has researched the collection and created a discography at the Smithsonian: ?A DISCOGRAPHY OF VOLTA LABORATORY RECORDINGS? AT THE NATIONAL MUSEUM OF AMERICAN HISTORY?


More information on the Volta Laboratory can be found on Wikipedia or by searching on the name.


This is a summary of the media studied so far.? There is clearly a large variation in the physical characteristics of the discs and the methods employed at the Volta Lab.

RPM are estimates. New records are highlighted in red.

Cat. No







Variable density photo disc

~2 mm



~100 ?


Variable area photo disc

~4 mm





Lateral cut plated reverse copy

700 microns

100 microns

350 microns



Green wax vertical cut on brass

1.7 mm

135 microns

~35 microns



Wax on composition board, vertical cut, cracked

600 microns

95 microns

10 microns



Wax on composition board, vertical cut

400 microns

50 microns

5 microns



Wax on composition board, vertical cut

600 microns

60 microns

10 microns



Foil on plaster on cardboard, vertical cut

140 microns

250 microns

150 microns



Wax on metal cylindrical mandrel + rotation


90 microns

9 microns



Cat. No. 287881-A

This disc contains a direct recording of A.G. Bell?s voice, as documented in the notes stored with the artifact, and verbal statements.? The disc is extensively cracked and the wax appears to be delaminating from the binder board base.? There is also extensive particulates and debris in the grooves.? This disc is judged to be unplayable with a stylus method.


P. Feaster discography

? Date: 15 April 1885

? Inscription [in wax around center]: Record made April 15 1885 | AGB and C.A.B. | to test reproduction of numbers. | Disk A. G. B. No. 1

? Format: White or transparent wax composition on binder?s board, cardboard ~243 mm; spindle hole ~25 mm; outer diameter of wax coating ~230 mm; inner diameter ~71 mm cracked surface (was stored upside down when found); single, well modulated groove band.

? Documentation: A paper is stored in the cabinet with the recordings: Contents of Disk AGB No 1. | Disk with Numbers | Experiment made April 15th 1885 | 1, 2, 3, 4 &c?to 50 | 10, 20, 30, 40 &c to 100 | 100, 200, 300 &c to 1000 | 1000, 2000, 3000, &c to 10,000 | 10,000; 20,000; 30000 &c to 100,000 | 100,000 200000 30000 [sic] to 1,000,000 | 3571 3571 3571 | 3571 123,941 125,873 | 1,945,876 35,900 33878 | 48715 790042 4,530,870 | $45.? $89.73 $4029.46 | 35 cents. 25 cents 30 cents 50 cents | half a dollar a quarter dollar | 3 dollars & ? $5? $7.29 | $10? $3785.56 | This record has been made by Alexander Graham Bell in the presence of Dr. Chichester A. Bell?April 15th on the 15th of April 1885 at the Volta Laboratory 1221 Connecticut Avenue, Washington D. C. In witness whereof?hear my voice | Alexander Graham Bell -- Referenced in Floyd K. Harvey, ?Mementos of Early Photographic Sound Recording,? SMPTE Mot. Imag J. 91:3 (March 1, 1982), 237-244, as evidence favorable to the existence of a recording of Alexander Graham Bell?s voice; however, Harvey did not make the connection with 287881-A.

? Related item: Box ?E?

Top image is a detail of the disc showing the inscription ?Record made April 15, 1885 by A.G.B and C.A.B. to test reproduction of numbers?, (C.A.B. is Dr. Chichester A. Bell, chemist, member of the Volta Association and cousin of A.G. Bell).? Middle image is of the entire disc.? Bottom image is taken from the data collected by the confocal probe.? This image is a mapping of the circular disc to a rectangular format.? The dark lines from left to right are grooves.? This is a depth image where darker is deeper into the surface. The yellow line indicates the basic movement of a stylus, or the direction of time.? The vertical offsets correspond to the various cracks in the surface.? The horizontal line across the middle corresponds to the frame width of the confocal probe.? This image covers two frames and about 3.6 mm radially on the disc.


Full recording raw Smithsonian\Audio\2013 Release\287881-Merge.wav   YouTube Version

Full recording filtered Smithsonian\Audio\2013 Release\287881-Merge-DCFIR.wav   YouTube Version

?This record was made?.? filtered Smithsonian\Audio\2013 Release\This-record-DCFIR.wav   YouTube Version

?Hear my voice?? raw Smithsonian\Audio\2013 Release\Hear-my-voice-raw.wav   YouTube Version

?Hear my voice?? filtered Smithsonian\Audio\2013 Release\Hear-my-voice-DCFIR.wav   YouTube Version


Cat No. 287860.2


This disc is composed of foil on plaster of Paris, on a cardboard backing.? It appears to be an attempt, made in 1885?, to reproduce a recording made in 1881 by a molding process.? The original master also had a number of generations involving electrotyping as well.? The surface of this disc varies by 2 mm in height which is unusual.


P. Feaster discography:

287860 [1]

? Date: ca. 1885? (from 1881 master)

? Format: cardboard with plaster layer and tinfoil surface.

? Duplicated from: 287881-B = 287669

? Related item: Box ?F? associated with catalog number 287860


287881-B = 287669

? Date: 29 December 1881

? Older description for 287669: Heavy, 10-3/4-inch metal disk, ?-inch thick, lead body, copper face, deep grooved record, with hole and recess in center. Marked, ?S. T. December 29, 1881.? Noted as ?not found 1937,? but the description matches the duplicate-numbered 287881-B and is presumed here to be the same object.

? Inscription [raised, mirror image, in copper near center]: S. T. Dec. 29th 1881.

? Format: Copper electrotype disc cemented with plaster of paris to type-metal base with raised outer lip and spindle hole and other holes at center. Total external diameter ~275 mm; external diameter of copper disc ~268 mm; interior diameter of copper disc ~84 mm; diameter of spindle hole ~22 mm. Trace pitch ~1.3 mm per rotation, raised vertical cut phonogram with recessed groove between rotations; trace runs counterclockwise from periphery, so ?original? would have run clockwise from periphery.

? Documentation: THN 5:22-30, 34-36, 46-47. Content (transcribed at THN 5:29): T-r-r-r.??This record was first made in paraffin-wax by the voice; an electrotype in copper was then taken from it; and this iron phonogram from which the sounds are being reproduced was transferred from the copper electrotype. The original phonogram in the paraffin-wax was made on the twenty-ninth day of December eighteen hundred and eighty one. I am a magnetical Graphophone, what are you? To be, or not to be, that is the question. How is that for high?? T-r-r-r, etc. THN 5:47 reports that this electrotype negative was severely damaged in the process of dubbing it twice to an iron disc (possibly 287670*).

? Duplicates: 287860 [1]; 287898; possibly 287670*. The first two don?t match the experiment for which the disc was originally prepared and are likely to have been created later, perhaps around 1885.

Profile measurement across grove from left-to-right. Groove depth about 0.25 millimeters

Profile measurement along the vertical (time) direction.? Groove amplitude is ~0.150 millimeters.

Raw audio file: Smithsonian\Audio\2013 Release\287860-BL100-D1-MERGE.wav

Filtered audio file:Smithsonian\Audio\2013 Release\287860-BL100-D1-MERGE-DC-FIR.wav    YouTube Version



Cat. No. 312123


In this case the ?record? was an entire recording machine and the sound bearing media was integral to the assembly.? The unit was placed in the beam of the scanner and rotated by an external drive system.


Notes from P.Feaster discography:

? Date: Final recording made September 1881. Machine was in use for similar experiments throughout the preceding summer.

? Format: Edison phonograph with widened groove filled with wax and cut with a vertical recording.

? Inscription (in ink, on attached card): The following words and sounds are recorded upon the cylinder of this Graphophone: ?T-r-r?T-r-r?There are more things in heaven and earth Horatio, than are dreamed of in our philosophy?T-r-r?I am a Graphophone and my mother was a Phonograph.

? Documentation: THN leading up to 3:44, Notes accompanying Volta Laboratory sealed package of October 1881.



Left: View of machine.? Center: During scan at Berkeley Lab. Cylinder is rotated by plastic timing pulley. Right: Close-up under the confocal probe.


Full recording raw: Smithsonian\Audio\2013 Release\wax-graph--44100-MERGED.wav   YouTube Version

Full recording filtered: Smithsonian\Audio\2013 Release\wax-graph--44100-MERGED-DCFIR.wav    YouTube Version 

Below is a simplified explanation of the process used to non-invasively scan the artifacts from the Volta Laboratory collection.? Data is acquired optically so that delicate or damaged materials are protected.

Research supported by the Institute of Museum and Library Services, the Smithsonian Institution, and the Library of Congress.


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