Johannes Müller,1 writing about the ear in his monumental handbook of physiology, stated that he could produce a snapping sound in his ears associated with contraction of the palatine muscles and elevation of the soft palate. He said, "If immediately afterwards I emit a humming vocal tone while my mouth is either closed or only slightly open, this tone has an extraordinary resonance." He could not explain this phenomenon but believed that it had something to do with the contraction of the tensor tympani muscle; while he had given much thought to the function of the eustachian tube, he did not correlate the phenomenon with its opening. He believed that it is continuously open. It was Toynbee,2 in 1853, who concluded from experiments on himself and from the tendency to swallow while descending in a diving bell that the eustachian tube is normally closed and opens only during bell that