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 in Oman Stirrup flew BAC Strikemasters during the Dhofar War in the close air support and interdiction roles, giving him valuable battle experience of the use of air power in counter-insurgency operations. After he returned to Great Britain in 1975, Stirrup was posted to No. 41 Squadron where he flew the SEPECAT Jaguar in the fighter reconnaissance role. Stirrup went on to serve in an exchange tour in the United States where he flew the all-weather tactical reconnaissance RF-4C Phantom. Promoted to squadron leader on 1 January 1980, Stirrup was serving as a flight commander on No. 226 Operational Conversion