The otologist is continuously faced with the problem of evaluating the function of the eustachian tube, not only in civilian practice but also in industrial and military practice. The lack of simple quantitative tests has made this difficult. A great deal of use is made of the Politzer bag, the eustachian catheter and the bougie. These instruments permit only a qualitative evaluation of tubal function. The results obtained in this way are exceedingly difficult to define. Since normal tubal function is not defined quantitatively, one has no good criteria for recognizing pathologic states of the eustachian tube.
In any consideration of tests for tubal function one must keep in mind that inadequacy of tubal function appears under two separate circumstances and that these must be differentiated. First, there are the common daily demands on the tube that arise from the slow and small change in pressure of the air mass
PERLMAN HB. QUANTITATIVE TUBAL FUNCTION. Arch Otolaryngol. 1943;38(5):453–465. doi:10.1001/archotol.1943.00670040472006