Threshold shifts induced by exposure to impulse noise with different peak pressures and the same energy density spectrum

Current hearing conservation criteria utilize peak pressures as one of the primary measures of magnitude. Peak pressure in conjunction with a measure of duration is translated into an indication of the hazard associated with a given impulse. Historically, it is not difficult to understand why peak pressure was chosen as a basic parameter. It is relatively easily determined. However, the empirical basis for using it as an indicator of auditory hazard goes little beyond the crude correlation between peak pressure and intensity. The experiment reported here directly compared the effects on hearing threshold of impulses with peak pressures differing by 8 dB whose energy density spectra were identical. Twenty‐four chinchillas were used as subjects, four groups of six animals each. Group one was exposed to 100 high‐peaked impulses at 147‐dB peak pressure. Group two was exposed to 100 low‐peaked impulses (139‐dB peak) which had the same energy density spectrum as the 147‐dB high‐peaked impulses. Group three rece...