There are many machines which have auditory warning signals. But these signals are so similar to each other that they may be confused. Sometimes people feel uncomfortable about these sounds. In this study, impression of auditory warning signals was examined in relation to the verbal meanings given to the signals. Two kinds of verbal meanings were prepared for each sound. Subjects were divided into two groups and asked to learn the sounds with the verbal meanings attached to them. The accuracy of recalling and the impression of the sounds were examined. Results showed that the verbal meanings given to the sounds had significant effect on the impression of some sounds, but little effect on that of the other sounds. To transmit correct information, appropriate physical variables should be selected for each auditory warning signal.