Observations of 10-, and 30-Hz P wave spectral amplitudes from earthquakes and explosions are compared with the Archambeau <1968, 1972> earthquake model featuring a P wave falloff of ω-3 beyond the corner frequency, a modified Brune <1970, 1971> earthquake model with ω-2 falloff, and the Sharpe <1942> explosion model which has a ω-2 falloff. The Archambeau and Sharpe models have been, in part, the basis of a proposal by Evernden et al. <1986> that high-frequency (≈30 Hz) seismic energy could provide an effective solution to the problem of detection and identification of low-yield coupled and fully decoupled underground nuclear explosions. The observations of earthquakes show an increase in spectral amplitude with moment approximately in agreement with the ω-2 falloff model and, for larger moments, in disagreement with the ω-3 model. Comparison of theoretical and actual seismograms narrow-band filtered at 30 Hz shows that in part the increase in spectral amplitude of earthquakes is due to the complex and long duration of the rupture process and not because of an increase in an impulsive first arrival like that characteristic of an explosion. The 30-Hz amplitudes for explosions show much scatter, and many events have a spectral falloff greater than the ω-2 predicted by the Sharpe model. Whether this is due entirely to attenuation or is the actual source spectrum is not determined. High stress drop earthquakes are predicted to have larger spectral amplitudes than the Shaper model. Thus any discrimination technique using high-frequency P wave spectra should probably take into account differences in pulse shape and amplitude in the time domain. ¿ American Geophysical Union 1988