Find a plant or bacterial culture or some kind of life form that grows really fast and leaves evidence of its growth patterns, and then, under laboratory conditions, vary the environment in various ways so that the evidence of the growth of the organic matter is apparent. Push the variance of the environment toward things like sound to see of you can develop a capability to read an environment like a recording. Rather than simply looking for visual evidence that could be translated directly into sound it would probably make sense to look for ways you could optimize the evidence-bearing capability of a plant - so that if you played say a certain frequency of sound it would significantly effect the growth of the plant because for instance the wavelength of the air vibration was close to size of some element of the system that is integral to the growth process.
-- JesusHChrist, Jan 01 2013

random, halfbakery