Engine howling at high speeds. What is it?

When I hit about 45-50 my engine or something towards the front of the car begins to howl/whistle pretty loudly. It is inconsistent. It will happen once and a while when I am normally driving but is much more prone to happen when my air conditioning is on. It is not related to RPM’s in any way, only speed. I do not know what it is, please help!!

Thank you.