After selecting a username and a pitch pair, you will be shown a list of short audio files that play two tones. The time between the start of one tone and the start of the next is small. Listen to the audio and select which tone sounds first, the higher one or the lower one. Only one file in the list has the tones start simultaneously. When you have made all of your selections, click on the 'Submit answers' button. (This page may not work in Internet Explorer. Try Firefox or Chrome.)
User:Previous Results - The headings show the time in milliseconds between the tones. Blue times are for the lowest note sounding first; red means the higher tone was first; green means they were simultaneous. Each user's scores are color coded according to their answers.