The earliest citation in Wikipedia is from 1883, and it is a question and answer: “If a tree were to fall on an island where there were no human beings would there be any sound?” [The asker] then went on to answer the query with, “No. Sound is the sensation excited in the ear when the air or other medium is set in motion.”
So, if this is truly the origin, they knew the nature of sound when the question was first asked.
The earliest citation in Wikipedia is from 1883, and it is a question and answer: “If a tree were to fall on an island where there were no human beings would there be any sound?” [The asker] then went on to answer the query with, “No. Sound is the sensation excited in the ear when the air or other medium is set in motion.”
So, if this is truly the origin, they knew the nature of sound when the question was first asked.