On the W-Notching of Tympanograms

Abstract

The so-called W-notching of tympanograms can be explained if some realistic assumptions are accepted about the dependence on the pressure in the external auditory meatus of the acoustical resistance and the acoustical reactance at the eardrum. Sets of susceptance and conductance tympanograms can be classified in four groups according as the pairs of tympanograms show, respectively, 1 and 1, 3 and 1, 3 and 3 or 5 and 3 extrema. The appearance of a W-pattern in the admittance proves that for a certain p interval the ear becomes mass controlled. The theory also shows that for higher frequency probe tones no pathology is necessary to explain W-notching.