It sounds like the plot of a spy story, instead we are talking of reality, particularly of a research published in the Science journal conducted by a team of experts and that will be presented at the International Conference on Cyber-Physical Systems which takes place these days in Vienna.
These researchers placed powerful microphones in proximity to the working platform of a commercial Printrbot printer and have started the job to achieve 3 figures: a small triangle, a small square and a standard size key. The theory is ispired by the methods for voice recognition technologies and and reconstructed in a 3D source file properties with an accuracy of 78% in the case of two geometries of 92% in the case of the key.
The result is obviously amazing and is a prelude to a new reverse engineering method although doubts on ethical and quality implications. The scientific evidence has not yet clarified in fact what the results might be placing the printer in a room with sound interference or other typical noise production. Even less is possible to provide the misleading use which may be made of a similar method of capture for industrial espionage
In future anyone launching a smartphone application for the registration of sounds might get the project file that a designer, an architect or a company is implementing within their own studio or workshop. The simple sound recording will not give useful elements to copy machine settings (operating temperature or filament extrusion temperature) but maybe it could be “perfected” by the presence of termic detection systems or of electromagnetic fields.
If the theory turns out to be applicable 3D printer manufacturers should run to equipe their machines with a soundproof cover to ensure the confidentiality of data, far from the ears of Big Brother 😉 .