  We study the evolution of spectra of acoustic waves that are generated in the
convection zone and propagate upward into the photosphere, where we compare the
simulated acoustic spectra with the spectrum observed in an Fe I line. Although
there is no pronounced 3 min component in the spectra generated in the
convection zone, there are dominant 3 min features in the theoretical spectra,
in agreement with the observed spectrum. We interpret the occurrence of the 3
min features as the response of the solar atmosphere to the acoustic waves
which shifts high frequency wave energy to low frequencies. We also find
qualitative agreement for the acoustic power between the wave simulations and
the observations.
