Sonotubometry with perfect sequences: First results in pathological ears

Abstract Conclusion: Sonotubometry with perfect sequences (PSEQ) was able to detect eustachian tube (ET) openings in both normal and pathological ears. Impaired ears showed ET openings in almost all cases; however, these proved to be not only less frequent, but also with lower amplitude and shorter duration. Objectives: To investigate the function of impaired ET under physiological conditions, using a novel kind of sound stimulus for sonotubometry – the PSEQ. Methods: Twenty otologically healthy subjects (40 normal ears) and 32 patients with ear diseases (40 pathological ears) were examined sonotubometrically using noise signals with an ideally flat spectrum (PSEQ). Dry swallowing, water swallowing, and Toynbee maneuver were used to induce ET openings. Analysis was performed regarding the frequency of occurrence, duration, amplitude, and form of the ET openings. Results: PSEQ allowed the detection of an ET opening in all 40 normal ears (91% of the performed maneuvers) and in 87.5% of the ears with impaired ET function (but only 47% of the maneuvers). The average amplitude of the openings in healthy ears was 16.86 dB, the average duration was 363 ms. In diseased ears these values were significantly lower: 9.73 dB, p < 0.001 and 280 ms, p < 0.05.