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severely tested ; the mildest speaking, coughing, or sneezing even, is 

 always disagreeably felt thereon. 



But to pass to the attendant sonorous phenomena : the rippling 

 of the air in the tube at each elevation and depression of the ribs 

 expresses itself by a souffle., and every word I utter is taken to the 

 labyrinth directly through the tube with a force that proves annoy- 

 ing ; observations which plainly evince why the Eustachians are 

 usually impervious, and why they almost never open except at that 

 instant of deglutition, or of the reverse act, eructation, which occludes 

 the glottis. 



From numberless observations, I am able to affirm that the faculty 

 of audition is not at all deteriorated by patency of the tubes, how- 

 ever the ordinary use of the ear may be perplexed by sounds enter- 

 ing the tube. Nor does stretching the membrana tympani, by aug- 

 menting or diminishing the aerial pressure on its inner surface, 

 enfeeble hearing. 



I will now turn to observations made upon my left ear when it 

 was deafened. I show that the external meatus was unaffected ; and 

 if I rubbed my finger over the skin covering the bone behind the ear, 

 or carried the ticking of a watch to the bottom of the meatus by 

 means of a metallic probe, and then did the like to the other ear, I 

 heard well, and as well upon one as the other. Hence the labyrinth 

 and acoustic nerve remained healthy, and the drum alone was 

 affected. Singing noises in the head had been developed just to the 

 same extent as hearing had been blunted, phenomena that for three 

 weeks before an instantaneous cure remained quite unchanged. 



The noises were caused by the circulation of the blood about the 

 drum, for they rose and fell as the circulation was quick or otherwise. 

 And I was led to the belief that these noises were not created by any 

 morbid change of local circulation, but that, by a morbid change in 

 the acoustic properties of the tympanum, ordinary movements of the 

 blood thereabouts were heard in a multiplied manner ; for the 

 click and souffle from air entering the Eustachian tube, as heard 

 in the healthy ear, were wonderfully magnified in the deaf one. 

 The louder souffle, that of eructation, normally but very weak, 

 even when the intruding air strongly forces outwards the membrana 

 tympani, in the deaf ear was always a very pronounced bruit. And 

 a couple of other sounds from distinct sources generated within the 



