Noises have to be heard to be sure of a diagnoises. Take it to a a garage.
AnswerI had a similar problem like this, does the noise continue for only a few moments after you turn? My problem was a small exhaust leak. They are had to distinguish though, youre better to take it to a garage.Both answers are worth considering , however usually when you have a noise turning in one direction it is a front wheel bearing , in this case probably the left hand side as when you turn right it puts extra force to the left side tire , consider it a warning sign and get repaired as soon as possable to avoid damage to brake pads and rotor , you can check this yourself by jacking the car up (allowing the wheel to hang) now try to lift the tire while pushing against the top of the tire should be NO play if you can move the tire the wheel bearing is bad . Mike
Anytime I've ever heard a humming noise when turning the steering wheel on any vehicle,It has always been due to low power steering fluid
Check and see if your power steering fluid level is low.
Many things can cause that, the simplest cause being lack of power steering fluid.
Check your power steering fluid
With the car stopped turn the wheel fully left then right and see if you still hear the hum. It sounds like the power steering fluid is low, causing a hum, or whine.
A bad alternator. Turning the steering wheel all the way is very demanding on the power steering which draws power from the engine and can cause the idle to dip down. A weak alternator is usually the cause for the stalling.
Low steering fluid can cause a steering wheel to whine when turning. A worn steering belt can also cause a steering wheel to whine when a car is being turned.
ummm power steering
Check out the bearings in the steering column and the knuckles in the steering shaft
If the sound occurs only when turning, (left or right) the most likely cause is a loose power steering belt. First check to see if the belt is tensioned correctly, or in need of replacement.
when the pump is going out it will make a humming noise from the bearings even if the resivore is full.
Check the power steering pump for the cause of the noise. I sounds like the pump is causing the whining and is either low on fluid or possibly going bad.