The lumped constant theory given earlier [J. Acoust. Sec. Am.26, 947(A) (1954)] has been extended to take into account the finite area of contact between cushion and head. The modified theory is based on the premise that the cushion and flesh have infinite bulk modulus, and leads to the conclusion that there is an effective cover area which is equal to a linear combination of the “inner” and “outer” areas. The physical methods of attenuation measurement described earlier have been further developed to permit the determination of both the amplitude ratio and the phase shift in transmission. Such measurements make it possible to calculate the impedance of the flesh under the cushion at frequencies between 30 and 500 cps. The preliminary values of stiffness and resistance (8 × 107dyne‐cm−1and 3 × 105dyne‐sec cm−1) are, respectively, less by a factor of 6 and greater by a factor of 10 than the magnitudes of the corresponding mastoid parameters recently determined by Corlisset al.and Dadsonet al.This suggests that the low‐frequency impedance presented by the head to a circumaural ear defender cushion is mainly determined by the viscous and highly compliant flesh rather than the comparatively rigid skull.