The last few years have seen rapid progress in solar interior modeling, and standard solar models (SSM) now predict a p-mode oscillation spectrum which agrees, within the estimated uncertainties in the physical input, with the observed oscillation spectrum of the Sun (Guenther et al., 1992a, 1992b; Guzik & Cox, 1993). This is the result of a number of improvements in the input physics, most notably the advances in opacities for the solar interior (Rogers & Iglesias, 1994) and the low temperature regions of the Sun (Kurucz, 1991). The agreement between the observed solar p-mode frequencies and the frequencies predicted by the SSM is not yet perfect, however, and understanding these discrepancies has become a focus of our research.