Vibrate up to the pitch or above?

The question of whether to vibrate above the pitch, or only up to, is a controversial discussion that I have had with some of the most talented professionals throughout the world. Some musicians believe that the center of the wave, or vibrated tone, is the tone that is registered by the ear. However, most believe that the ear registers the highest tone reached, which is what I firmly believe, play, and teach.
What do you think?