Sound is a potent tool for getting the player immersed in the game and to keep them thinking about the game long after they have finished it.
Immersion for the player is something every game designer strives to achieve. Immersion is when you lose yourself in the game, it becomes your only focus, and you forget about the real world for a bit. A few ways sound can help immerse the player are ambient sound effects, interactive sound effects, and background music.
Ambient sound effects can help the game world feel real by adding depth to a scene by giving the player spatial awareness with audio. In the real world, you hear a sound, and your brain jumps into action, trying to figure out the direction and distance of the sound. When the ability to determine this is not there, it can create a disorienting effect, breaking the player out of the immersion. Thankfully, most game engines now have spatial audio components that allow you to place the sound source in the game world, and the engine manipulates the sounds, so they seem to come from that spot, even in stereo. If the game has ambient sound effects like crickets in a field, have the sound come from a couple of points in the scene so as the player moves, the sound seems to change dynamically, and this can help the world feel real by allowing the brain to figure out where and how far the sound is from the player.
Interactive sound effects are sounds that play in reaction to player input, like firing a gun, reloading a clip, opening a door, and pushing a button or footsteps as the player moves. These effects give the player an audio response to their actions, letting them get feedback through sound and sight instead of sight alone, and this can help them become more immersed in the game by making it just like in the real world when you act you get a response from multiple senses.
Music is amazingly powerful at influencing emotions. How many times have you heard a song and had it either make you feel an emotion you were not or had a song amplify what you are feeling tenfold. It can make the player feel happy, sad, scared, or even like they can take on the world. To me, there is nothing better than a great soundtrack to get you immersed in a game. When you listen to a track from a game soundtrack later, if done right, you can even envision that moment in the game and the memories of playing it. A perfect example of this for me is pretty much any ‘Warthog Run’ in the Halo series, with my favorite one probably being from Halo 3. Every time I hear that track, I can remember the excitement and thrill of that run.
Sound is a great way to immerse your player into the game, whether ambient sounds like crickets, a machine whirring, or a babbling brook, or interactive sounds like gunshots and footsteps or a button press, or music to set the mood of the scene. Each plays a part in immersing the player.