ALTERATION IN THEACTIVITY OF THEEIGHTHNERVEPRODUCED BYRAPIDCHANGES IN THEBLOODPRESSURE IN THENORMALHUMANBEING. ByDR. J.FRANKPEARCYandDR.DANIELB.HAYDEN. In clinical hypertension there is frequently a decrease in auditory acuity for the higher (but not the highest) tones. Such patients commonly complain of tinnitus aurium and vertigo. That these symptoms are caused by the high blood pressure per se is a gratuitous assumption. It is equally likely that the pathologic structural changes associated with the hypertension produce the symptoms. In some instances, hypotension has been associated with vertigo, tinnitus and a similar defect in hearing. These symptoms are found occasionally in severe cases of anemia. One is tempted to speculate on a common cause for the symptoms in the three cases. Such a cause might be an insufficient supply of oxygen to the internal ear. There is