Let’s try to imagine for a moment our tympanum as a thin strip with its elasticity. As can be seen in the illustration above, (f1) the eardrum in a normal working condition, is perfectly vertical.
As can be noted instead, in phase two (f2 the eardrum is stimulated by the external pressure which increases by 1 BAR / ATM every -10m. while the internal pressure decreases, decreasing the volume of indoor air and this Physical phenomenon is the Boyle-Mariotte Law which says :
“At constant temperature, the volume of a certain quantity of gas varies inversely with the pressure to which it is subjected. “
This means that by increasing the depth of immersion and then the external pressure, the volume of gas contained in the body cavities and in the equipment is reduced.
At this point before you feel the pain in your ears, it is good to intervene with a mechanical maneuver and methods taught in the course Open Water Diver PADI there are three: Marcante-Odaglia, Valsalva, Toynbee. In this article I will explain the one most used by divers and which also applies in other circumstances, such as, for example, while landing the aircraft, or while you’re driving downhill from a mountain with your car.
Here’s how to execute the Marcante-Odaglia.
- You must compensate the ear for the first symptoms of discomfort, without waiting to feel pain.
- When you feel discomfort, the first thing is to go up 1 mt. because the external pressure exerted towards the interior may decrease.
- Bring the two fingers: thumb and forefinger, over the nostrils, tighten them and keeping the lips sealed, gently blow air. This operation, will ensure that the pressure inside the middle ear, Increases its pressure, while externally is decreased (see p.2). This maneuver of mechanical compensation of the ear, will create a counter force that goes from the inside to the outside, bringing the gable in its regular position, as shown in the figure above (f4) .
- Performed the Marcante-Odaglia maneuver, if the annoyance has disappeared, resume the underwater descent.
The importance of participating in a course Open Water Diver PADI or one or more courses of PADI Specialty Underwater Courses greatly enriches one’s abilities regardless of whether you may be at the first experiences or that you are already experienced divers.
Author: Copyright © Francesco Cordone All rights reserved
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