Objective and quantitative analysis of the Eustachian tube function is considered to be of great importance in diagnosis and treatment of a variety of ear diseases. Many tests for evaluating this function have been devised and clinically employed. Utilizing an aerodynamic technique, an evaluation was made to establish a simple and reliable method which enables a detailed analysis of tubal dysfunction. Using pressure transducers, simultaneous recording of the pressure in the external ear canal and the nasopharyngeal cavity was made during Valsalva's maneuver and degulition. In 60% of one hundred normal tubes, a similar pattern which was regarded as typical for a normal tube was found. The recording may be edivided into 5 segments a-b, b-c, c-d, d-e, e-f, and f-g. Every point and segment have physiological meanings and judgement of tubal function was made by merely observing aerodynamic pattern. - 2. It was considered that the sole muscle responsible for tubal opening is the tensor. - 3. (a) When we blocked the stellate ganglion (sympathetic nerve system), we usually saw the obstructive pattern on a curve. (b) When we blocked the pterygoplatini ganglion (parasympathetic nerve system), we saw the open pattern on curve. -4. We found that the most important muscle for tubal opening is the tensor palatini muscle, cutting of this muscle by suturing results in a consistent increase in tubal patency. In our clinic, these procedures were utilized in patients with severe tubal disturbance and postoperatively these patients were followed up by Tubo-tympanoaerodynamic graphy and tympanometry.