A summary of audiometric and histological results from 423 chinchillas that were exposed to high-level (150 to 160 dB peak SPL) blast waves produced by four different sources will be presented. The four sources, in an anechoic environment, produced Friedlander waveforms whose A-weighted energy spectra peaked at 0.25, 1.0, 2.0, or 4.0 kHz. The experimental data were organized to illustrate the effects of sound exposure level (SEL) and spectral energy on auditory system trauma. SEL was increased through increases in peak SPL and number of impulse presentations. The results show that the rate at which pathology (audiometric or histological) grows with increasing SEL is strongly influenced by both the different spectra of the four sources and the spectral details of an individual source. The results can be interpreted to indicate that, for a given octave band, equivalent amounts of energy do not produce equivalent auditory effects but are influenced by the dominant energy-carrying band of the blast wave. [Work supported by USAARL.]