I've had a whining sound in my car before. The faster I went, the louder and more annoying it got. As I slowed down it would get quieter and if I came to a standstill, it would sometimes disappear altogether.
But once I started off again, the whining started and if I put my foot down, it got annoyingly loud and whiney again.
But once I'd dropped the other half off, it stopped