got a whinning noise!!

Hi folks..I could use some insight here.

I have noticed a new whinning type of noise. It varies upward with speed, becoming audible at about 25MPH. Hot or cold, doesn't make a diff. Most prominent when accelerating, less prominent when engine braking. Does not vary by engine speed, nor whether running straight vs turns. There appears to be a direct correclation to vehicle speed...the fater I go, the higher the pitch. and the harder I go, the louder.

At 60MPH, on cruise, it's almost bearable to live with, but again on any engine load it becomes very noticible.

It sounds a bit like a listening to a jet engine (thought it was a cool sound at first) , or like running with snow tires. Defninitely not a grinding noise....more turbine-ish.

Any thoughts?