High-pitched whine engine noise

I have a 2008 TL Nav/AT with 115,000 miles (The only part replaces in the engine compartment has been the serpentine belt about 6 months ago). The vehicle makes a whining noise that grows louder and higher pitched as I rev the engine up. The noise is similar to what you hear from a dentist's drill. This happens when I am driving and while in neutral. If the radio is on AUX with no input it pics up on it and amplifies the noise.

I suspect either the water pump or the alternator.

Video/Sound: " title="Engine Noise - YouTube" target="_blank">Engine Noise - YouTube

Engine noise with radio on - YouTube