If you can reproduce the noise with the car standing still it must be relatively easy to find.
Have someone turn the wheel while you are listening, preferably with a car stethoscope. Be careful not to stick your head or any other body part under the car while it is running. It can be a the steering pump, ball joint or any other suspension part. Checking play by hand is generally not enough, the ball joints of the suspension are under great pressure and can be completely worn before you can feel the play.