Play the video and listen to the tones, and adjust the volume to a level that is comfortable. 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 by pressing the left arrow on your keyboard (and move the sound right by pressing the right arrow). When the sound is closest to the centre of your head, pause the video and make a note of the number on the screen.
Note: If the sound moves in the wrong direction (e.g. left when you press the right arrow), your earphones are the wrong way round.
Once you’ve finished, press next to move on to the next tone.
UCL Ear Institute 