[LibGDX] How to check if Object is in certain part of camera?

       My camera can zoom in and out and I already figured out how to check if an object is INSIDE the camera with the frustum, but I want to check if an object is to the left or right side of the camera (The middle being its width divided by two). I'm also trying to use this to figure out how to play sounds in a certain part of the speakers, which I suppose is the pan variable of the sounds.