Sounds and music in a game can either completely immerse the player, or jerk them to be aware of the unnaturalness in the game world. Sounds must convey and enhance the action experience; flow naturally for what is present on the screen; and contribute to the scene and world building. If a character is walking on wood with heavy boots, it shouldn't sound like soft leather on dirt. People can tell when something doesn't sound quite right, and it causes them to become uncomfortable. To keep the player engaged with the game, a good sound design is crucial. 

Background music adds to the atmosphere of the game. What is the character doing or how are they feeling- what is the emotion you are trying to convey to the player: is it sad? nostalgic? anxious? ecstatic? An upbeat music piece can indicate a feeling of joy


In addition, background music for voice acting clips can support the emotion in the script and sets the mood for the listener. 

blah blah interested in sound or sound effects but haven't had much experience