  Acoustic waves excited in the photosphere and below might play an integral
part in the heating of the solar chromosphere and corona. However, it is yet
not fully clear how much of the initially acoustic wave flux reaches the corona
and in what form. We investigate the wave propagation, damping, transmission,
and conversion in the lower layers of the solar atmosphere using 3D numerical
MHD simulations. A model of a gravitationally stratified expanding straight
coronal loop, stretching from photosphere to photosphere, is perturbed at one
footpoint by an acoustic driver with a period of 370 seconds. For this period
acoustic cutoff regions are present below the transition region (TR). About 2%
of the initial energy from the driver reach the corona. The shape of the cutoff
regions and the height of the TR show a highly dynamic behavior. Taking only
the driven waves into account, the waves have a propagating nature below and
above the cutoff region, but are standing and evanescent within the cutoff
region. Studying the driven waves together with the background motions in the
model reveals standing waves between the cutoff region and the TR. These
standing waves cause an oscillation of the TR height. In addition, fast or
leaky sausage body-like waves might have been excited close to the base of the
loop. These waves then possibly convert to fast or leaky sausage surface-like
waves at the top of the main cutoff region, followed by a conversion to slow
sausage body-like waves around the TR.
