Cochlea a protein motor called prestin on their outer membranes; it generates additional movement that couples back to the fluid–membrane wave. This "active amplifier" is essential in the ear's ability to amplify weak sounds. The active amplifier also leads to the phenomenon of soundwave vibrations being emitted from the cochlea back into the ear canal through the middle ear (otoacoustic emissions). Otoacoustic emissions are due to a wave exiting the cochlea via the oval window, and propagating back through the middle ear to the eardrum, and out the ear canal, where it can be picked up by a microphone. Otoacoustic emissions
Catholic theology of the body creation of God. God created the body like a work of art in his image. This creation reflects God’s intelligence. The human body is (eikon) somehow similar to God. To be completed as a mirror of him, is the task for every Christian. Unlike the human body, the soul is an image of God. The body cannot be an image of God, otherwise God would look like a human being with a human body. Only the soul can see God, but it is caught between the flesh and spirit. It constantly has to make a choice between the two. Origen