The purpose of this study is to build a monaural auditory display to convey four pieces of directional information (upward, downward, rightward, and leftward) to users effectively and intuitively without the need for wearing headphones or preparing more than one speaker. We prepared five types of monaural auditory displays consisting of triangle wave sounds and conducted an experiment to investigate which kinds of displays succeeded in conveying the four pieces of information to participants. As a result, we could confirm that one of the prepared monaural auditory displays, designed as a “progress bar” on the basis of the mental-number line and spatial-number association of the response code effect, succeeded in conveying the four pieces of information more effectively compared with the other candidate sets (its average correct rates were 0.88). This result thus strongly shows that this monaural auditory display was quite useful for conveying primitive spatial information to users.