The best way to understand what IntelliAudio®/MultiTalker® does is to think of a time when you were in a crowded room with multiple conversations going. You are having a conversation with a good friend when all of the sudden you hear your boss' voice somewhere near you. Imagine your boss mentions your name! I think you might get the idea. Although your friend is still speaking to you, your brain is listening to your boss. And unfortunately, he wasn't talking about giving you a raise.
IntelliAudio®/MultiTalker® in the cockpit works in the same way, I like to call it "The Cocktail Party Effect". It allows you to listen to two or more coms at the same time but having the ability to pay attention to the radio that is important at any instant in time.
For example, you have com 1 on ATC while on Com 2 you have ATIS. Most ATC calls are for other aircraft, but listening and copying weather is a necessity especially if you are flying IFR in IMC. You have to have the weather at the airfield you will be landing at before you can select the approach.
The moment you hear ATC call your N number, you will be able to immediately change your attention from weather to ATX. It's the IntelliAudio®/MultiTalker® that lets you take advantage of the power of your brain.