The spectra of normal incidence transmitted compressional and shear waves are inverted to yield intrinsic (frictional) and apparent (scattering) attenuation factors as a function of frequency. This inversion is made possible by the observation that, to a first approximation, scattering and intrinsic attenuation are additive [Spencer, 1982 and Richards and Menke, 1983>. Two additional assumptions are needed; that poisson's ratio is constant and that intrinsic attenuation is mainly due to shear. The technique is tested against numerical calculations, and is shown to work at least for wavelengths larger than the scale length of the layering. The inversion requires wide-band observations and is quite sensitive to noise in the data.