I ran across an interesting comment from a student of acoustics that reminded me of the discussion of the "silence of the heavens ... fear of that silence" paragraph at the end of the In the House of Tom Bombadil chapter.
http://mcmansionhell.com/post/169367229546/looking-around-on-sound-part-1-noise
Emphasis added...
Anyway I'm not suggesting that JRRT had experience in an anechoic chamber. Just a mirror of modern science in his text.
http://mcmansionhell.com/post/169367229546/looking-around-on-sound-part-1-noise
Emphasis added...
As a student of acoustics, I’ve had the displeasure of being in an anechoic chamber and experiencing the suffocating terror that is total silence, a silence so strong you can hear every sound made by your internal organs, a silence so strong people can only stand being in an anechoic chamber for mere minutes.
Anyway I'm not suggesting that JRRT had experience in an anechoic chamber. Just a mirror of modern science in his text.