Why Does My League Voice Keep Disconnecting?

You need to make sure that the volume is turned up to a level that is audible, check to see that the wires (if you have a wired headphone device) are not worn out or loosely attached, and check to see that they are plugged into the appropriate port, among other things. After you have ensured that these things are in order, you should check to see whether the voice chat option in League of Legends is operational.