An earlier paper described the distribution of sound pressure in the auditory canals of a number of subjects in a plane progressive sound field. At a given frequency, the ratio of the sound pressures at the eardrum and at the entrance to the ear canal was found to be greater than unity and essentially independent of the orientation of the observer with respect to the sound source, as might be expected from theory. With this ratio known, it is possible to determine, with relative ease, the sound pressures at the eardrum as a function of azimuth from pressure measurements near the entrance to the auditory canal. By positioning a probe microphone at the entrance to the ear canal and comparing the sound pressures there with the free‐field pressures at the subject's location an estimate of the obstacle effect of head and pinna is arrived at. Adding the known pressure increase in the auditory canal yields a measure of the total obstacle effect of the human head and auditory canal. The subjects were placed in front of a loudspeaker in a room essentially free from acoustic wall reflections. The measurements of the sound pressure at the entrance of the left auditory canal and in the free field in the absence of the subject were carried out by means of a small probe microphone in the frequency range extending from 200–6000 c.p.s. A range of azimuths of 360 degrees was covered in 45‐degree steps. If it is assumed that the two auditory canals are alike and that the head is symmetrical about the median plane, the ratio of the sound pressures at the left and right eardrums can be readily computed from these data. This ratio is of importance in the mechanism of binaural localization. The average for six male subjects was compared with the values obtained by Sivian and White from threshold measurements and was found to be in fair agreement.