Sounds like an airplane, 100% related to car speed, not engine RPM or gear. Why?
What is your question?
When accelerating, the noise gets louder and higher in pitch, when slowing down, the opposite. It makes the noise in Neutral, Drive, or Brake (engine breaking). When going down a hill in Neutral and accelerating under its own weight, it acts the same. Everything about the sound is related to car speed. It does not vary with load (accelerating up a hill) or lack of load (coasting down a hill) in Drive or Break. In a rear wheel drive car, I would be looking at the differential (likely) or the throwout bearing (Not likely as to no variance under load). There is a almost unnoticeable vibration associated with this sound. The transmission is a CVT.
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I have read quite a bit about this "Airplane noise" and there seems to be quite a bit of debate whether this is wheel bearing or transmission. I would be interested in your comments on that debate. If Front hub bearing, how do I identify which one?
Apply park brake.. Jack up one front wheel.. Start engine and put trans in gear, increase speed up to about 30mph, let off accelerator .. Hear noise at any time?.. Now do the other side same way!! .. Been working for me since the late 70's on front wheel drive vehicles!!
I have read quite a bit about this "Airplane noise" and there seems to be quite a bit of debate whether this is wheel bearing or transmission. I would be interested in your comments on that debate. If Front hub bearing, how do I identify which one?
Apply park brake.. Jack up one front wheel.. Start engine and put trans in gear, increase speed up to about 30mph, let off accelerator .. Hear noise at any time?.. Now do the other side same way!! .. Been working for me since the late 70's on front wheel drive vehicles!!