Abstract
I have measured the retraction grade of the tympanic membrane resulting from the acoustic reflex of the tympanic muscle, by use of my myringogoniometer or myringo-cinematograph. These objective procedures have been applied to the measuring method for the recruitment phenomenon in the cases of deafness. The advantages of my retraction grade measuring of the tympanic membrane are the following: (1) This method is based on an objective procedure apart from the patient's tonal sensation. (2) Each ear can be naturally measured separately because of the bilateral character of the reflex. (3) Even in a case with symmetrical audiograms of both ears we do not have any restrictions in performing the test. (4) Even in the cases of infants with an uncertain answer the measurement can be carried out as well as in the cases of adults. Furthermore, the objective deduction of the auditory threshold is possible with them. (5) This method is usually not influenced by the existence of pathological changes in the middle ear compared with Metz's impedance method.