phase change could be wrongly interpreted in TD as a travel time shift [@Cal09ab; @Cal09aa].

So, there are many processes going on here: fast/slow conversion/transmission of upward travelling waves at $a=c$; slow wave reflection or transmission, depending on the acoustic cutoff and the magnetic field inclination $\theta$; fast-to-Alfvén conversion near the fast wave turning point; partial reflection of the fast wave to re-enter the seismic field; further fast/slow conversion/transmission as the fast wave passes downward through $a=c$. In totality, this is too complicated to model analytically. However, knowing the physics of the constituent parts, a full numerical simulation can provide valuable insight. The novel aspect explored here is to simultaneously calculate the TD travel time shifts $\delta\tau$ and upward acoustic and Alfvénic losses in a simulation as functions of $\theta$ and $\phi$ (for selected frequencies and horizontal wavenumbers).

The considerations set out above indicate that active regions are truly wounds in the surface of the Sun. They allow waves and wave energy to escape from the interior cavity wherein they are normally trapped, but also allow their depleted, phase-shifted, and mode-converted remnants to re-enter and infect the local seismology that we rely on for information about the sub-surface. The purpose 