Intense low-frequency tones produce masking-period patterns in which the masking of a higher-frequency tone burst varies by up to 25 dB over the period of the masker. In this experiment, observers were asked to match the loudness of partially masked test-tone bursts in one ear by adjusting the level of unmasked bursts presented to the other ear. It was found that the variation in masked threshold over the period of the masker also affects loudness matches. This effect on loudness, although it decreases in size with increasing level above masked threshold, persists even 25 dB above masked threshold.