The long-standing argument centers around outer hair cells, which are rod-shaped cells that respond to sound waves. Located in the fluid-filled part of the inner ear called the cochlea, these outer hair cells sport tufts of hair-like cilia that project into the fluid. The presence of outer hair cells makes mammalian hearing more than 100 times better than it would be if the cells were absent. As sound waves race into the inner ear at hundreds of miles per hour, their energy--although dissipated by the cochlear fluid--generates waves in the fluid, somewhat like the tiny waves made by a pebble...
