Gerhardt's sign

(gerTiart) [C. J. Gerkardt; Berlin physician, 1833-1903.] x. The tympanitic resonance on percu ion over a pulmonary cavity, the long diameter of which is from before backward, is of lower pitch when the patient sits than when he lies if the long diameter is from above downward, the reverse is the case. 2. Immobility of the larynx in dyspnea due to aortic aneurysm.