strange nosie

I have a pontiac grand am 2004, and I am hearing strange noises from the front end of my car but the thing is why I drive straight I hear the noise but when I turn a corner it smooths out,I have asked a couple machanices and they told me that my hub bearing needed to be changed out on the drivers side, so I got it changed out, but it hasent changed a thing, I still hear the noise. So I decided to ask for a second opinion, and what I was told was that my transmittion had to be changed? And when I went back to the machanic who had changed out my bearing, he told me that it was not the transmittion but my bearing and that he may have tighten it too tight?