They are the font of your overall abilities, but yes they are passive in a sense.
Think Talents in a sense of general things you can do. Like I can climb, or I can use my senses to percieve things around me. They are essentially just basic skills/knacks that people can do. But yes, for the sense of activating, they are passive, so they are always active.
There are specific Active Skills you can get that can enhance certain Talents (like one that you get automatically at Observe Rank 5 that is very, very useful) that are voice activated.
But yea, Talents are passive otherwise. They are just things you do.
