Abstract
In orrder to compare the impedance audiometer ZO73A with the impedance tympanoscope ZS 330 (both from Madsen Electronics), we examined 50 children who had beer admitted to the ENT Department and 24 children from a kindergarten. There proved to be a good correlation between the middle ear pressure, except that ZO330 showed a rather lower middle ear pressure. As regards compliance too there was a good correlation. The ipsilateral stapedial reflex was rather labile, and in 68% of the ears the two instruments showed conformity, while in 15% only ZO73A and in 17% only ZS 330 could elicit the reflex. When the middle ear pressure was lower than ∼100 mmH2O, the ipsilateral stapedial reflex could be elicited in only 25% of the cases, even though the middle ear pressure was equalized.