Or just wait until it warms up and see if the noise is still there. Like Bigswede said it is most likely your power steering pump. But I dont know how cold it gets where you live, but it could just be whining from the cold. When I lived in Chicago area, the winters there are freezing. And I use to come out of school hop in my trooper and the brake lines would be frozen and the steering pump would whine a little like your talking about. Sometime it just takes a while for the fluid to warm up, or maybe your pump is damaged now. Hope that helps