Here is a bit of an insight into what each option does within Sonar settings.
Spatial Audio - Similar to 7.1 surround sound, you can adjust how "close" each of your virtual speakers, are in your headset as well as how immersed you are within your game.
Volume Boost - Helps with in-game volume before being sent to your headset.
Smart Volume - Helps adjust the volume coming into your headset to ensure it comes out clear and not distorted.
ClearCast AI Noise Cancellation - Helps reduce any audio interference coming to your headset, weather its jets flying over or a hair dryer being used. Click here for a video example!
Noise Reduction - Similar to ClearCast AI but not as strong the Noise reduction allows you to choose how much background noise as well as how much keyboard or mouse clicks you can hear using the Impact option.
Noise Gate - Is used for those quiet times when you don't want to say anything it will make sure no noise is being sent to your mic until you start to talk!
Compressor - Make sure your voice isn't too high or too low for your friends and chat can't hear.