Today I discovered this article: http://www.musicandmeaning.net/issues/showArticle.php?artID=3.2
which made me very excited. The author Iegor Reznikoff did exactly what I have been fantasising about and would love to do explore the prehistoric caves with sound.
Some years ago I passed a little cave on a walk and went in not too far just till it became really dark and did play with sounds, singing. It was a very intense experience. The sound becomes so tangible and physically intense. And all the senses become extremely sharp in the dark. Since that time I have been waiting for another cave to continu that exploration.
Some time later I did find some interesting information on archeological research by studying the acoustic qualities of prehistoric sites, mostly in the UK.
Here in France I found some information about musical instruments used since prehistoric times. Flutes made out of bones, lithopones which are quite fascinating too, and some other instruments. But this finding of today is about researching the caves with sound and investigating the relationship with the density of the paintings and drawings. And the philosophical background is closely connected with my former experience in art therapy and psychotherapy.
Can't wait to continu to learn more about this.