As a method of rating sounds with respect to the expected community response, ISO(1971). ISO R 1996, "Assessment of noise with respect to community response" (International Organization for Standardization, Switzerland), recommends the measurement of the Aweighted equivalent sound level Leq. The usefulness of Leq for road-traffic sounds has been demonstrated in various studies. For impulse sounds, however, research into the adequacy of Leq has been very limited. The present laboratory study provides a further test of the adequacy of Leq as a descriptor of annoyance. in one condition, all impulse sounds had the same level, whereas in the other eight conditions the levels of the impulses could differ either by 6 or by 12 dB. The proportions of the impulses with high or low sound levels were 90% vs 10%, 75% vs 25%, and vice versa. Sixteen subjects compared the annoyance caused by the impulse sounds (G) with the annoyance due to road-traffic sounds (T). They adjusted the level of either T or G in such a way that these sounds were just as annoying as the standard G [Leq = 40 dB(A) ] or T [Leq = 45 dB(A) ] sounds. The results from one group of subjects showed that the degree of annoyance was about the same for all conditions, whereas the results from another group of subjects showed that Leq may overestimate the annoyance in at least some conditions. The present data, therefore, mildly support the effectiveness of Leq as a predictor of annoyance.