Figure 2.

The solid curve shows the free-field-to-eardrum transfer function.

Note. This function is the difference in sound level between a point at the position corresponding to the center of the listener’s head (with the listener absent from the sound field) and a point close to the eardrum, for a sound field with frontal incidence. The dashed curve shows the corresponding function for diffuse field conditions. This is the transfer function from the sound field to the eardrum averaged over all possible angles of incidence.