2009 CR-V begins a high pitch noise when reaching speeds over 55mph. It disappears at about 50 mph when slowing down. What is causing this?

 

First try and identify where on the vehicle the noise is coming from. Checked the wheel bearings, I have worked on vehicles where the bearing had no play but made terrible noises. So you many have to remove the knuckle and spin the hub off the vehicle to pinpoint the noise.