Beethoven - the Unanswerable Question...

I have not yet read anything about the issue that confronted me this week; so, please contact me through "comments", if any of you know of any paper or thesis written about this:
It occurred to me that the issue of Beethoven's music poses an unanswerable reality; and that is, during the extended period of total deafness, which contains the Master's greatest incarnations, he could not have heard his own creations as you and I have, let alone countless others through the generations who have heard and lived with them.
In his insular world devoid of any outside sound, his music came back to him in a way we could not possibly grasp; on the other hand, Beethoven could not possibly have known the precise entity of his creations as we have heard them; as these creations have had to travel through the air and reach our ears and inner spirit in the manner known to us, simply by our listening.
So, unlike any other great composer, his music reached him and us in the most disparate manners known to the world of music - how strange; and yet, compellingly beautiful is the arcane nature of this unique reality.