Sound Test is a feature where the player is able to listen to music and sound effects from the video game. Sound Test is featured in numerous Sonic the Hedgehog games, but originally in earlier games for Sega Genesis, it has been as hidden feature and part of the Level Select.
Like Level Select or Debug Mode, it is accessed by inputing certain actions, which has to be done on a certain part of the game to do so. However not every game in the series has Sound Test as a hidden feature, as the player can access the Sound Test which is available from the start.
One of the first games in the series to feature Sound Test at options is Sonic the Hedgehog 2, while later other games such as Genesis versions of Sonic Spinball and Sonic 3D Blast it is able to found at options menu too. As before mentioned games have Sound Test being normally featured, they have been also part of the those games' hidden Level Select menu. In Sonic the Hedgehog CD, if the game has been completed by getting good ending of the game, the player unlocks the feature called DA Garden from the title screen of the game, which includes Sound Test and being able to play Little Planet at the sky background along with other minor objects at the screen. The normal, yet hidden Sound Test can be find from the game by using cheat code. Knuckles' Chaotix version of Sound Test features more complex system, with being able to test different audio modes. By getting this, the player has to configure the certain codes on each two above sets on the Color Test by entering "06", "0B" and "11" on the second set of digits, making 1971 beside the "Mars". In Sonic Jam, the player can listen music tracks and sounds effects at Sonic World's "Music Shop", which are taken from original Sonic the Hedgehog, Sonic the Hedgehog 2 and Sonic the Hedgehog 3 & Knuckles.
Later games such as Sonic Adventure, Sonic Adventure 2, Sonic Heroes and Sonic the Hedgehog (2006) (dubbed as Music Room), the Sound Test has become as extra feature, which can normally found at Options menu of the game. In Sonic Advance, there is a Sound Test that can be used from the beginning of the game, but in Sonic Advance 2 and Sonic Advance 3, the player has to unlock after clearing the game with certain way. In Sonic Unleashed, collecting Records will let the player listen to the music tracks from the game on the Gramophone or Audio System. In Sonic Generations, the player is able to listen collectible music from the game at Collection Room.
- In Knuckles' Chaotix, by configuring third set of digits with "00", "08" and "17 " under the title "Mars" and 0117 should be reading on number beside at the Color Test, Amy Rose makes a hidden cameo appearance on the Sound Test screen, with dancing and saying "Cool, sweet & catchy!".
- In hidden Sound Test of Sonic Chaos, if the player move in a quarter circle and presses or , Sonic can be seen shooting out a sparkling fireball, resembling the Hadoken from the Street Fighter series.