Cyclical changes in nasal airway resistance and middle ear pressures.

The relationship between unilateral changes in nasal airway resistance and the ipsilateral middle ear pressure were investigated in 8 otologically and rhinologically normal adults over the course of 7 1/2 h under laboratory conditions. Despite mean changes in unilateral nasal resistance of 0.75 Pa/cm3/s associated with the nasal cycle, no correlation existed with changes in ipsilateral Eustachian tube function, as judged by serial middle ear pressure recordings (r = 0.06, r2 = 0.00, p = 0.461). Middle ear pressure in healthy adults in a controlled environment remained very constant (mean = -6.71 +/- 0.52 daPa). 69% of middle ear pressures were equal to or above 0 daPa, which represents evidence in favour of a net positive production of middle ear gas.