Comparison of pure tones and noise stimuli in sonotubometry.

Sonometric data on the Eustachian tube opening response to swallowing and to pressing the mandible down were evaluated in 51 normal ears and 62 ears with chronic disease. Testing with a narrow-band noise which was centered on 7 and 8 kHz gave the best results. The limit for a positive response was set at 3 dB, and of the normal ears, 80% showed a positive response in a short routine test. The data correlated reasonably well with surgical results. If test results point to tubal insufficiency, measures should be taken to prevent the formation of retraction pockets.