Negative pressure and loss of hearing in tubal catarrh

Abstract

Summary. It was possible to demonstrate a resorption of air in the tympanic cavity by means of the pneumophone. At the same time some new clinical aspects of the tubal catarrh were found. Stenosis of the tuba is a notion entitled to keep an important place in otology. Complete obstruction causes a negative pressure of about 50 cm of water. In cases of less severe stenosis the loss of air is replenished by the sucking power of the middle ear to a pressure which exactly indicates the resistance of the tuba (f. i. 30 cm). In cases of tubal catarrh only loss of hearing to 20 decibel for tones under 4000 H. is caused by a negative pressure. A more marked loss of audition for the lower tones and loss of hearing for the high tones, must be due to other causes, such as enclosure of the windows and impedement of the ossicular chain. Loss of hearing caused by spasm of the musculus stapedius could not be proved. Spasm of the tensor tympani could be demonstrated by us, but is of secondary importance.