my voiceover turned itself on and won't quit talking and I can't access my screen to turn it off, can I fix this from my computer?

When I touch my screen, nothing happens. It barely lets me slide to unlock and I can't access what I want to do. Meanwhile, the voiceover somehow turned itself on and it won't shut up! It keeps telling me what screen it's on and what buttons I'm touching and it's driving me crazy! Any suggestions? The screen isn't dirty or anything.