There is a high pitch noise/whining came from the front side of my car when I was driving on the highway around 70mph (it also happened before on local way). It lasted a few seconds (or minutes) each time and continued happened for an hour. It won't disappear when I speed up, slow down, turn on/off the AC or even stop. Even I turned off the engine, the noise was still there for another 5 to 30 seconds.
I've uploaded the video, the noise happened around 0:10, 0:21, etc.
‪Volvo S60 High Pitch Noise‬‏ - YouTube

If anyone know what's going on? My local dealer told me they did not meet this situation before.