We investigated detrimental effects of irrelevant auditory stimuli on reading comprehension. In Experiment 1, 12 participants read three kinds of text and summarized them succinctly and between the tasks, they listened to street noise, street noise containing unclear human voice, classic music, and chat of disk jockeys and some combinations of these sounds. The threshold above which feeling of the task performance being disturbed occurs was determined. We found that the chat was most detrimental (i.e., lowest threshold) and the street noises were less (high thresholds). In Experiment 2, 18 participants listened not only to the normal sounds of street noise, music, and chat but also to their reversed sounds. The mean threshold for the normal or the reverse chat was about 5 db lower than the thresholds for street noise and music. These results suggested that the participants felt more disturbed, not by semantic features, but by acoustic features of auditory stimuli, i.e., by abundant segments of amplitude pattern.