The fine‐structure acoustic‐impedance curve of the ear obtained from normal humansin vivois used to develop a network model of the middle ear. First a model representing the middle ear during stapedius muscle contraction is constructed, representing the middle ear with the stapes blocked. A further development adds a circuit corresponding to the input impedance of the cochlea as seen from the stapes. To decrease the influence of the eardrum itself, the eardrum was coated with collodion. Good agreement is found between the input impedance measured at the ear and calculated from the model over the range investigated, from 200 to 1800 cps. The effect of the collodion coating is investigated and the earlier model is modified to fit the input impedance of the uncoated ear. The agreement is not so good as in the case of coated drum. The reason is suggested to lie in the complicated motion of the uncoated eardrum, which could not be represented by the simple circuit of the model.