When you Talk on CSS your Plantronics Gamecom headset only makes a buzzing noise

According to the instructions on the CSS for the game Counter Strike Force, it says that you should have a sound card with a headset. You don't say which headset you are using. If you are using a wireless one it may be picking up interference, which could cause buzzing. If you are using one that has a sound card then it may have a loose connection when plugged in. Damage to cords and connections are a common liability when it has been used fairly often. If a cord has a loose connection in the wiring somewhere it can cause the buzzing in your ears. If this is still under warranty you will want to get it replaced.