Direct interactions between modes and dynamic 3D convection shift mode frequencies (part of the surface effect) and coherently dampen or excite modes. These interactions arise from terms in the conservation equations for mass, momentum and energy. I will show my results for a deep atmospheric 3D simulation of solar convection. In Rosenthal et al. (1999) we introduced a 'turbulent' component to the adiabatic exponent, γ1, to describe how turbulent pressure responds to modes. At the time we didn't know its form, but I hope my talk can lay that discussion to rest.