Play the video and listen to the tones. Try to find the point in the video where the tones sound like they are closest to the middle of your head.
Move the sound to your left or right by pressing the left and right arrows on your keyboard. When the sound is closest to the centre of your head, pause the video and make a note of the number on the screen.
Then press next to move on to the next tone.
UCL Ear Institute 