Hotkeys elt your assign single- or multiple-key combinations for Teamspeak functions such as Muting speakers/mic, moving around different channels, connecting to servers, etc. These Hotkeys will works no matter the game/program  running. So long as Ts3 is running, they will work.

In TS, go to Settings - Options, then hit the Hotkeys tab at bottom-left. Click the green "Add" button towards the bottom. In the new window, click "Show Advanced Actions". Expand "Switch to Channel;" twice, and double-click whichever room you wish to create a Hotkey for. You can set a single key, or any combo of modifier_regular keys. For example, use shift-alt-1/2/3 to change to Welcome/Co-Op1/Away channels, respectively.