Experiments with synthetic seismograms from two wells let us confirm a conclusion of O'Doherty and Anstey that seismic attenuation due to layering alone arises from a combination of the transmission losses through the interfaces of a layered subsurface and the generation of intrabed multiple reflections. Transmission losses lower the amplitudes uniformly at all frequencies. Intrabed multiples tend to raise the amplitudes at the low-frequency end of the spectrum and lower those at the high-frequency end. For the wells studied, intrabed multiples higher than fifth order (10 msec delay) were unimportant. Attenuation due to layering accounted for 1/3 to 1/2 of the total frequency dependent attenuation estimated from field seismograms at the well locations.