3D Measurement Resurrects Voices from the Past

Posted by: 20. May 2014

In 2010, a machine called IRENE (Image Reconstruction Eliminate Noise, Etc.), being operated by its inventor Carl Haber, was able to scan a 125-year old wax cylinder embedded with sound waves.  The machine translated the signals and replayed the words, “Hear my voice, Alexander Graham Bell.” At that moment, Haber became the first living person to ever hear Bell’s voice.

According to Alec Wilkinson, in a New Yorker article, “A Voice From The Past,”  people have been recording their voices and sounds since around 1860. Up until recently, however, these recordings could not be heard, because IRENE, or something like it, didn’t exist. Even back in the 1800s, recording sound waves was a fairly rudimentary task. A phonautogram (something like a vinyl LP, but cylindrical in shape, about the size of a coffee can) could be made by fastening a sheet of paper around the cylinder and darkening the paper with carbon from a burning lamp. Then the rotating darkened paper would be etched by the tiny movements of a pig’s bristle generated through its connection to a diaphragm stretched over a barrel that captured the wave energy from nearby sounds.   Thousands of phonautograms have been found and saved by archeophonists (curators of artifacts containing sound waves).  Only recently, and only because of the invention and construction of five IRENEs, have any of these recordings been heard.

But more traditional commercial recordings have been played for nearly 100 years. What is it about these phonautograms that have prevented them from being heard before the invention of IRENE?  In short, they are so fragile that the slightest contact with anything like a record player needle, stylus, or reader used to receive the sound wave signal, would permanently destroy it.

Enter 3D Scanning.  One of the most critical components of IRENE is the OGP SmartScope® non-contact  multi-sensing optical 3D measuring device that is used to read the representation of the sound waves embedded in the wax or other material surfaces on the phonautograms.  Without contact with the phonautogram and therefore without damage to it, the SmartScope® is able to read the sound wave graph, as if it were scanning the surface of a machined metal part, then feed the coordinate data to a computer program designed to translate the values into a digital format. The computer then plays the file like an MP3 that reproduces the originally recorded sound.

Once again—manufacturing technology to the rescue.  This time, to save our culture and history.


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