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
History of beliefs about the human body manuscript is recorded in the Yellow Emperors Inner Cannon, and it being recorded in this way represents the attention to the individuals perspective in creating therapies like acupuncture to treat body ailments. The Inner Cannon was revised by natural Philosophers of the time and the approved version of the Han Court and became a foundational text for the ideals and perceptions of the human body. It focused on Qi, Yin and Yang balance, and Five phase theory to explain health can disease. Referred to as the life force of the body, or the means by which the body is able