This would be the perfect opportunity for some of you with a large shotgun collection to compare the sound of barrels, by tapping them just as you might to look for a loose rib. The sound will vary, even among fluid steel barrels, depending on length and thickness. But it seems plausible that a difference of pitch could be found between fluid and Damascus which would be more easily recognized without the noise of firing.
The fact that Walsingham might note the difference in use, is not surprising because he was obviously an athlete comparable to professionals of today. Their sensory reflexes surpass the average person.
I just did this test for you Volleyfire.
Four sets of sound barrels, all 12g SxS, thirty inch.
Webley & Scott, Damascus has a low note.
E. James, Twist is a bit higher note.
I. Hollis & Sons, Steel is a note higher
W. Cashmore, Steel is noticeably a couple of notes higher again.
The Hollis barrels are 3" chambered & heavy, while the Cashmore is 2 3/4 chambered & lighter.
I do know that on a nut farm where I used to shoot pest control that the boss could tell which of my guns I was shooting on the day. This was using the same ammo & each gun shot to a different note.
O.M