In my novel, a character makes the claim that sound can be recorded by the panels in a door. The door panel vibrates with sound, according to him, and those vibrations are recorded analogically, very much in the way sound can be recorded in an emulsion by rearranging metal particles embedded in that emulsion using an electromagnet, or on a wax disk via a vibrating needle.
According to him, the panels in a door - even a very old door that has been floating in water for some time - contain the record of every sound that has been made in a room since the door was first hung there: Since wood is a living material that retains flexibility over very long periods and has a "memory," the wooden panel retains, according to him, the memory of its displacement in response to the sounds it has "heard." He refers to this as "kradasmolignic memory." He is looking for someone who can devise a way of reading that recorded information. There would be many potential uses. He would, for example, be able to recover performances by famous singers of the past currently thought to be lost forever, or conversations between historical figures. Fortunes might be made.
How would the fibers of the wood in a door panel actually record sound, if that were possible? And how could that information be read?