Fig. 3

Gentamicin concentration (ng/ml) in perilymph. Data were fitted to the eq. 2 as in Fig. 2 but there were significant differences between the model with gentamicin (n = 43) and without gentamicin (n = 44) (p = 0.0044), indicating that mannitol changed the permeability of the blood-labyrinth barrier. As in Figs. 1 and 2, many data points are congruent so they look like one datum. The parameterized equations for gentamicin concentration without mannitol, then was [\( y(t)=70\left[{e}^{-0.5t}+\left(1-{e}^{-{0.11}_{\left(t-4\right)}}\right)\right] \), and the equation with mannitol was \( \Big[y(t)=64\left[{e}^{-t}+\left(1-{e}^{-{0.31}_{\left(t-4\right)}}\right)\right] \)