It’s a Wednesday afternoon in Newton Centre, and James Phillips is learning how to see without seeing. With a blindfold on and instructor at his side, the functionally blind 21-year-old is tapping and sliding his Hoover cane — the red-tipped white aid — down crowded sidewalks, across major roads, and along the bumpy edge of a T platform. This is all part of a training regimen at the nearby Carroll Center for the Blind, where Phillips, who comes from upstate New York, is spending a few months. Carroll clients often use Newton streets to practice. The movement of the cane (which the Carroll Center helped develop after World War II) produces sounds like no other: the rhythmic tap-tap before each step, the scrape as it glides over a crosswalk, and the clang and thwack as it warns of the many obstacles to a safe journey — parking meters, mailboxes, benches, planters, curbs. Human courage and human senses, working in tandem.