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 Yang Qi energy where as a female has dominant Yin energy. Transgenderism, hermaphroditism and other variations of the body can be explained by the Yin and Yang Qi ideas of the body much better than the European counterparts. Other types of change in the world were classified by Wood, Fire, Earth, Metal and Water. Applied to the body these 5 forces were the Liver, Heart, Spleen, Lung, and Kidney. These representations of the physical world in the body was understood dynamically and represents a deeper connection to the non animate objects and surroundings of a human. The body was not