This experiment was conducted to determine whether perceptual asymmetries would emerge in a task requiring the discrimination of two auditory time intervals. The first interval (standard) was presented binaurally and the other one (comparison) monaurally. The intervals were either filled (continuous sound) or empty (duration between two brief sounds). A total of 24 right-handed participants (12 women, 12 men) completed the four conditions (two Ear×two Structure). The results revealed that filled intervals were perceived as shorter when the monaural signal was presented to the left ear than when it was presented to the right ear, whereas there was no ear effect for empty intervals. Interval structure was not a significant factor when the monaural signals were delivered to the right ear, suggesting a right ear advantage in duration estimation. Finally, temporal sensitivity was better with empty than with filled intervals, but this effect was independent of the location of the monaural signals. The results are discussed with reference to potential effects of attention and the role of structural aspects underlying perceptual asymmetries.