Cochlea to structures in the brainstem for further processing. The "stapes" (stirrup) ossicle bone of the middle ear transmits vibrations to the "fenestra ovalis" (oval window) on the outside of the cochlea, which vibrates the perilymph in the "vestibular duct" (upper chamber of the cochlea). The ossicles are essential for efficient coupling of sound waves into the cochlea, since the cochlea environment is a fluid–membrane system, and it takes more pressure to move sound through fluid–membrane waves than it does through air; a pressure increase is achieved by the area ratio of the tympanic membrane to the oval window, resulting in
Jock Stirrup – Iraq. Stirrup strongly backed Mohan's plan but noted that Mohan would need to be pressed hard to deliver and also supported with Corps forces. Austin was reluctant to provide support, wishing to focus on Mosul, but Petraeus agreed with Stirrup. However, this plan was overtaken by Maliki's decision to launch Operation Charge of the Knights. Both Stirrup and the American commanders were taken by surprise and were concerned about the lack of planning but Maliki was determined to launch his operation in late March. Operation Charge of the Knights led to the Battle of Basra which lasted from 25