Abstract: Air motion in the boundary layer (BL) greatly influences the locality of separation point behind which the BL separating the surface of sphere begins and obviously influences the drag of sphere in airflow. It was supposed that acoustic vibration may cause exchange of momentum between the different levels inside BL so that the airflow in the bottom of BL will be accelerated and the separation point will be pushed backwards when the characteristic wthickness of BL is comparable with the amplitude of acoustic vibrations. On the basis of this effects we can expect that the acoustic vibration will decrease ahe drag force exerted on a falling spherical drop. This effect may be called "lubrication". We have calculated this effect by means of the method given by лойуяский and gained an enlightening physical picture.