The contribution of stimulus-response compatibility to Stroop interference was tested in an auditory version of the Stroop test. The words “high” and “low” were presented in high and low pitches with either the pitch or the word designated as the relevant dimension. College students categorized the relevant stimulus dimension with a verbal response, a buttonpress, or a pitched hum. Significant interference occurred in the incompatible conditions (pitch-verbal, word-hum, pitch-button), but not in the compatible conditions (pitch-hum, word-verbal, word-button). The results indicated that stimulus-response compatibility was an important determinant of observed interference. It was suggested that stimulus-response incompatibility contributed to the response competition that presumably occurs in Stroop tasks.