Optical Scan Results on the Smithsonian Volta Laboratory Collection

Updated 12-Dec-2011

 

Some general references

·        This is the general website for the IRENE/3D optical scanning projects   http://irene.lbl.gov/

·        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

 

The files posted here are provisional. Unless otherwise noted a low pass filter has been applied.  In some cases (noted) additional noise reduction has been applied as well.  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.

 

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

Cat. No

Description

Pitch

Depth

Amplitude

RPM

287654

Variable density photo disc

~2 mm

NA

NA

~100 ?

287686

Variable area photo disc

~4 mm

NA

 

 

312119

Lateral cut plated reverse copy

700 mm

100  mm

350 mm

120

287920

Green wax vertical cut on brass

1.7 mm

135 mm

~35 mm

60

287700

Wax on composition board, vertical cut, cracked

600 mm

95 mm

10 mm

20

287701

Wax on composition board, vertical cut

400 mm

50 mm

5 mm

40

 

Cat. No. 287654-11

Large glass photo-disc with variable density stripe

 

 

 

Extracted sound file Smithsonian\Audio\Release\Example2-PD1-p93-44100.wav

Transcript based upon listening to audioSmithsonian\Audio\PD1-transcript-V1.pdf

Individual Segments

“H.G. Rogers”                                                                                      Smithsonian\Audio\Release\287654-HGRogers.wav

“It’s the eleventh day of March, eighteen hundred and eighty five”          Smithsonian\Audio\Release\287654-11th-day.wav\

Trrrrr….”                                                                                            Smithsonian\Audio\Release\287654-1st trill.wav

“ Mary had a little lamb….”                                                                  Smithsonian\Audio\287654-1st-Mary.wav

Trrrr… Mary had a little lamb….”                                                       Smithsonian\Audio\Release\287654-2nd-trill-Mary.wav

“How is this for high? Trrrr…”                                                              Smithsonian\Audio\287654-how-is-3rd-trill.wav

 

Cat No:287686-2

Large glass photodisc, variable area recording with notes “Barometer”, recorded at constant linear velocity

 

 

Extracted sound file Smithsonian\Audio\Release\287686_Barometer.wav

 

Cat No. 312119

Small electroplated lateral cut disc

 

Extracted sound file: Smithsonian\Audio\Release\312119_Lateral_Electroplated_Disc-120.wav

Speed set by ear to 120 rpm, low pass filter applied

Cat No. 287920

Green wax disc on brass

 

 

 

Pitch 1700 microns

Depth 135 microns

Amplitude 30-40 microns

60 rpm

Winds from the center out

 

Audio is “To be or not to….” From Hamlet

Extracted audio file: Smithsonian\Audio\Release\Example1-Green-p93.wav

i

Cat No: 287700

This is wax on composition board.  The disc has 5 large radial cracks which probably render it mechanically unplayable.  The groove modulation is vertical and the groove  is very wide relative to the later commercial cylinders.

 

 

 

 

Image from 287700 near the intersection of two cracks

Pitch 600 microns

Depth 95 microns

Amplitude 10 microns

 

Partial audio extractions in chronological : order: Low pass filter applied to all.  Additional noise reduction applied to the last two files. Speed set to 20 rpm.

Smithsonian\Audio\Release\287700_part1.wav

Smithsonian\Audio\Release\287700_part2.wav

Smithsonian\Audio\Release\287700_part3.wav

 

Notes on content:

It appears to be a man describing some sort of business or other arrangements, most words cannot be identified yet.

At 32 seconds into the first file are the words “in order to cover costs”.  This is repeated again in the third file which is from a different part of the disc.

 

Cat. No. 287701

This is wax on composition board, similar to 287700 but not cracked.

 

 

 

PRISM image from 287701, at the beginning of the audio.

Pitch 400 microns

Depth 50 microns

Amplitude 5 microns

Rpm = 40

 

The audio comes in two segments with a gap in between.

In the first segment it sounds like a man is reading a story.  At 51.8 seconds the voice suddenly changes to a high pitched “child imitation”.

In the second segment a man is reading a detailed description of  cotton mill.

 

First segment::

Filtered + Noise reduction:

Smithsonian\Audio\Release\287701_1sthalf.wav

Second segment

Filtered + Noise reduction

Smithsonian\Audio\Release\287701_2ndhalf.wav