Frenzel maneuver

The Frenzel Maneuver is named after (German ear, nose and throat physician and Luftwaffe commander). The maneuver was developed in 1938 and originally was taught to dive bomber pilots during World War II. The maneuver is used to equalize pressure in the middle ear. Today, the maneuver is also performed by scuba divers, free divers and by passengers on aircraft as they descend.
The Frenzel Maneuver is performed as follows:
By performing this technique, the compressed air is forced into Eustachian tubes, and thus into the middle ear. In situations where the ambient pressure rises (typical causes are decreasing altitude in the case of an airplane or increasing depth in the case of a diver submerging), the maneuver results in the equalization of the pressure on both sides of the eardrum.
Compared with the Valsalva maneuver, the Frenzel maneuver carries a significantly lower risk of over-pressurizing the middle or inner ear; given e.g. a nose-clip, it also allows hands-free equalisation. The maneuver can be done at any time during the respiratory cycle and it does not inhibit venous return to the heart. Effort to perform the maneuver is minimal, and it can be repeated many times quickly.