PROVIDENCE, R.I. — The voice Alexis “Lexi” Bogan had before last summer was exuberant. She loved to belt out Taylor Swift and Zach Bryan ballads in the car. She laughed all the time — even while corralling misbehaving preschoolers or debating politics with friends over a backyard fire pit. In high school, she was a soprano in the chorus. [time-brightcove not-tgx=”true”] Then that voice was gone. Doctors in August removed a life-threatening tumor lodged near the back of her brain.