There is an alternative feature which uses voice activation, meaning whenever you spoke into the microphone, it would activate the software, but Patrick Norton found that this did not work for him as well, since basically any loud noise in the room would activate the software, which is why he decided to ask a friend for discarded tattoo machine foot switches which he could use as a switch to activate Teamspeak.
He made use of Teensyduino, which is a smaller version of Arduino, and which could also operate as a USB device, which meant that Patrick Norton could “trick” the computer into thinking that the foot switch was another keyboard. He then proceeded to add the code to make the foot switch act as a third “Control” button which he then proceeded to bind to the Teamspeak software, leaving his hands free to concentrate on the game at hand, rather than fumbling for the key to enable TeamSpeak.
To check out his log on the entire process, just head on down to his website. Perhaps it might inspire you to make something similar as well, since it does look relatively inexpensive and not insanely difficult to code (he even provides the code on his website).