  We evaluate the pion and isobar propagators in cold nuclear matter self
consistently applying a covariant form of the isobar-hole model. Migdal's
vertex correction effects are considered systematically in the absence of
phenomenological soft form factors. Saturated nuclear matter is modeled by
scalar and vector mean fields for the nucleon. It is shown that the short-range
dressing of the pi N Delta vertex has a significant effect on the pion and
isobar properties. Using realistic parameters sets we predict a downward shift
of about 50 MeV for the Delta resonance at nuclear saturation density. The
pionic soft modes are much less pronounced than in previous studies.
