At long test tones, a hearing loss (abrupt drop at 3 kHz) is simulated in good approximation by presenting a continuous masking noise of appropriate spectral distribution to a normal ear. When shortening the test tones, the increase in threshold is systematically smaller for the impaired ear than for the ear with simulated hearing loss, showing normal temporal integration. Comparing threshold curves at long versus short test tones, for the hearing loss simulation only an upward shift is found. For the impaired ear, however, the magnitude of the hearing loss apparently increases with increasing test tone duration; moreover, the spectral characteristic of the hearing loss is quite different at long versus short test tones.