To control your TiVo box with your voice, your remote must be paired correctly to your TiVo box. For TiVo Mini users, you Mini must be connected to a DVR host. To pair your remote, select the Menu icon from the Home screen, then go to Settings/Remote, CableCARD, & Devices/Remote Control Setup.
If your remote is paired the activity light will flash yellow with each button press. If it is not paired, the activity light will flash red with each button press.