Sound as information Sound can inform a player when he or her plays the game. Speech For example, there might be an other character in the game that might tell you what to do next or what to search for. A good example for this is game called Infamous. In this game the other character is telling you what to look for to then progress to the other part of the game.
When you skip to 15 minutes of the video you can hear other character talking to you and informing you. Iconic/ Symbolic There might be also a Iconic sound that even thought you never played the game you will recognise the sound because is Iconic and Symbolic for this game. A good example for this is Sonic, as when he collects the rings you don't even have to see the gameplay all you need is to hear the sound and you will already know what game is it.
Metamorphic Some sounds will have metaphoric meaning. Metaphoric sound creates an extra layer of information. It signifies if there is something about to happen. For example Alien Isolation is a good example for this because when you will be quiet in the room when you play the game you will hear your character's heart beat. This will create a bit of tension for you as well so when the character's heart beat will start to beat faster you will start to feel scared and will lead to your heart speed beating faster too.