When I turn sharp corners, I hear a deep humming sound from my steering wheel area. It only happens when I make really sharp turns. It sounds like a miserable moan. The hydraulic pressure sound you hear is normal. When the steering is in right or left lock positions, the hydraulic pressure builds and makes noise.
Several things can be the cause.
First, check drive belt for the power steering pump. If the belt is okay, that leaves a faulty power steering pump or steering rack. A pressure test will eliminate a bad pump. That leaves the steering rack. Thank you for your time and consideration.