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
Heteropsammia cochlea The worm movements, in order to seek its food, allows the coral to avoid being buried. For cons, the coral is totally passive and dependent from its host travels. This small coral often has also a small parasitic mussel, "Lithophaga lessepsiana". Heteropsammia cochlea Heteropsammia cochlea, also known as walking dendro, is a species of small solitary coral in the family Dendrophylliidae that is native to the Indo-Pacific area. This small solitary free-living coral is not fixed to the substrate which the diameter does not exceed 2.5 cm. It has a very particular shape making it easily identifiable, composed of one