  We investigate the influence of a static, uncorrelated distribution of
charged impurities on the spectrum of bound excitons in the copper oxide
Cu$_{\text{2}}$O. We show that the statistical distribution of Stark shifts and
ionisation rates leads to the vanishing of Rydberg resonances into an apparent
continuum. The appearance of additional absorption lines due to the broken
rotational symmetry, together with spatially inhomogeneous Stark shifts, leads
to a modification of the observed line shapes that agree qualitatively with the
changes observed in the experiment.
