Slight whine from electric motor(s) maybe, I think...

So got 40K mile service recently as an FYI.

Now I'm hearing a bit of a whine usually around only at specific speed ranges eg 45-50 mph but not always sometimes its 30-35 mph. I'm obsessive with noises so not sure if its me or something is going slowly out. The dealer has in the past with other issues deferred to "within spec" so just wondering if anybody can share their experience with motors going out, was it instant or over time?