[Possibilities of error in tympanometry (author's transl)].

The possibilities for error in tympanometry are described. Mechanical difficulties in adaptation of the measurement tubes to the external auditory canal may be encountered. Tympanograms are discussed in patients with adhesive processes and otosclerosis which lead to incorrect results because of deviation from standard results. In the presence of adhesive processes, soft scars may produce a normal tympanogram so that the use of the Siegle speculum in connection with the Brüning magnifier is recommended. A normal tympanogram may also be absent in patients with otosclerosis. The height of the compliance curves generally does not allow conclusions as to the extent of the middle ear process so that in cases of doubt, the final determination of pathology can only be obtained by exploratory tympanotomy.