  This paper presents a novel technique to recover audio from sonorines, an
early 20th century form of analogue sound storage. Our method uses high
resolution photographs of sonorines under different lighting conditions to
observe the change in reflection behavior of the physical surface features and
create a three-dimensional height map of the surface. Sound can then be
extracted using height information within the surface's grooves, mimicking a
physical stylus on a phonograph. Unlike traditional playback methods, our
method has the advantage of being contactless: the medium will not incur damage
and wear from being played repeatedly. We compare the results of our technique
to a previously successful contactless method using flatbed scans of the
sonorines, and conclude with future research that can be applied to this
photovisual approach to audio recovery.
