First go to Options. Then play these sounds from Sound Test in this order: 19, 65, 9, 17. When the last sound starts you will hear the sound of 'when you collect a ring'. Go back to the Title Screen by pressing Start. Now, when you highlight 1 Player, hold A and press Start. You should go to Level Select. There should be a Sound Test there too. Play these sounds in this order: 4, 1, 2, 6. When Sound 6 starts, instead of hearing the real sound, you'll hear a sound when you collect a Chaos Emerald. Finally pick a level, collect 50 rings and jump to be Super Sonic! {Note this will not work on Sky Chase, the other level using the airplane or playing as Tails.}