Variations in round window membrane permeability and in perilymph flow could account for why hearing losses are observed in some patients.

Peak concentrations and gradients for gentamicin varied considerably between animals, likely resulting from variations in round window membrane permeability and rates of perilymph flow.

Results The located structures of the middle ear in the guinea pig include tympanic membrane, ossicular chain, oval window, round window, tympanic foramen of eustachian tube, facial nerve, etc;