The high rising intonation, also known as uptalk, upspeak, rising inflection or high rising terminal
James Gorman in an On Language column "Like, uptalk?":
I had no idea that a change in the "intonation contour" of a sentence, as linguists put it, could be as contagious as the common cold. But before long I noticed a Jekyll-and-Hyde transformation in my own speech. I first heard it when I myself was leaving a message. "This is Jim Gorman? I'm doing an article on Klingon? The language? From 'Star Trek'?" I realized then that I was unwittingly, unwillingly speaking uptalk.