Equalization Academy

Wherever you need to equalize, Equalization Academy will help you!

In every environment where the ambient pressure changes, we need to equalize the changes of volume and pressure in the middle ear.

We equalize when scuba diving, when freediving, in hyperbaric chambers and when landing on a plane.

Equalization Academy main topics

Organs involved in equalization

Middle ear
Eustachian tubes
Glottis
Soft palate
Tongue

Airshift techniques

Abdominal contraction
Reverse packing

Equalization techniques

Valsalva
Frenzel
Advanced Frenzel
Sequential Frenzel (mouthfill, non-constant pressure)
Hands free (VTO/BTV)
Mouthfill (constant pressure)

Dry skills

Otovent protocol
Balloon protocol
EQ-Tool
Water pipe

Airshift techniques

Freedivers only

The term shifting indicates the movement of a certain amount of air from the lungs to the oral cavity. Load, instead, refers to the amount of air stored in the oral and nasal cavity after the air shift: for example, the air between the tongue and the palate (N load, used for the traditional Frenzel maneuver) or in the cheeks (M load, used in advanced courses for the Sequential Frenzel and Mouthfill maneuvers).

There are two airshift techniques:

Abdominal contraction – the air is pushed upwards from the lungs.
Reverse packing – the air is sucked from the lungs.

Equalization techniques

There are various equalization techniques, in other words maneuvers that open the Eustachian tubes, connect the nasal cavity with the middle ear and balance its pressure and volume.

Valsalva

Flight & chamber · Divers

This technique is based on an abdominal contraction, which reduces the volume and increases the pressure in the lungs. The glottis is open, so the same pressure increase reaches the oral cavity, which is closed by the lips or by the tongue touching the palate. The soft palate is open, so the pressure also increases in the nasal cavity, which is closed by pinching the nose. Thanks to this pressure increase the tubes open and you can equalize the decrease of volume and pressure in the middle ear caused by the rising ambient pressure during the descent.

Traditional Frenzel

Flight & chamber · Divers · Freedivers

This technique moves the air inside the oral cavity by pushing the tongue upwards and backwards, which reduces the volume and increases the pressure with the glottis closed. The soft palate is open, so the same pressure increase reaches the nasal cavity, which is closed by pinching the nose. Thanks to this pressure increase the tubes open and you can equalize the decrease of volume and pressure in the middle ear caused by the descent. Some people can also open the tubes through a mechanical effect, which allows them to open at a lower pressure.

Advanced Frenzel

Freedivers

At a given depth, the air is moved into the oral cavity by saying the letter N and keeping the back of the tongue low, to increase the volume of the oral cavity. Then, moving the tongue from the T position to Ka and then H with the glottis closed, you reduce the volume and increase the pressure. The soft palate is open, so the same pressure increase reaches the nasal cavity, closed by pinching the nose, and the tubes open to equalize the middle ear during the descent. Some people can also open the tubes through a mechanical effect, at a lower pressure.

This technique can be practiced with a series of pressure increases, or with one light continuous movement that keeps the tubes open and the equalization pressure constant.

Sequential Frenzel

Freedivers

At a given depth, the air is moved into the oral cavity by saying the letter M: the air is stored in the cheeks to maximize the volume of the oral cavity, then the tongue is pushed upwards and backwards to reduce the volume and increase the pressure, with the glottis closed. The soft palate is open, so the same pressure increase reaches the nasal cavity, closed by pinching the nose, and the tubes open to equalize the middle ear during the descent. Some people can also open the tubes through a mechanical effect, at a lower pressure.

Hands free

Flight & chamber · Divers · Freedivers

After moving the air into the oral cavity, the glottis is closed with the soft palate open. The mechanical opening of the tubes automatically equalizes the decrease of volume and pressure in the middle ear caused by the descent. The hands free technique can be combined with Advanced Frenzel, Sequential Frenzel and Mouthfill.

Mouthfill

Freedivers

At a given depth, the air is moved into the oral cavity by saying the letter M, while inflating the cheeks, opening the lower jaw and lowering the back of the tongue, to maximize the volume of the oral cavity. With the lower jaw closed, pushing the cheeks and moving the tongue from the T position to Ka and then H reduces the volume with a light, continuous overpressure until the air in the oral cavity is used up, with the glottis closed. The soft palate is open, so the same pressure increase reaches the nasal cavity, closed by pinching the nose, and the tubes open to equalize the middle ear during the descent. Some people can also open the tubes through a mechanical effect, at a lower pressure.

Equalization on Freediving

	Valsalva	Frenzel	Advanced	Sequential	Mouthfill	Handsfree
Equalization technique	Pressure	Pressure Mechanical	Pressure Mechanical	Pressure Mechanical	Pressure Mechanical	Mechanical
Where does the pressure take place	Lungs	Oral cavity	Oral cavity	Oral cavity	Oral cavity	No pressure
Glottis	Open	Closed	Closed	Closed	Closed	Closed
Soft palate	Open	Open	Open	Open	Open	Open
Tongue	T, Ca or H	T, Ca or H	Progressively from T to Ca to H	T, Ca or H	Low position first, then progressively from T to Ca to H	Not significant
Charge	–	N – R.P.	N	M – R.P.	M – R.P.	N – M – R.P.
Air quantity into the oral cavity (0 → 6)	0	1	3	4	6	From 1 to 4

Dry skills

Otovent protocol

The Otovent is a medical device made of a latex balloon that is inflated with the nose through a special nasal cannula.

It is a great help when learning equalization techniques: by watching how the balloon changes, you understand how the tongue, the glottis and the soft palate are moving and where they are. With these exercises out of the water you learn the movements you need to equalize properly.

Balloon protocol

The Balloon protocol was developed to become aware of the glottis, the soft palate and the tongue.

With this protocol (8 exercises) freedivers train the Sequential Frenzel and the Mouthfill.

EQ-Tool

The EQ-Tool is a digital device designed to improve equalization skills: it measures the pressure in the nasal cavity during the equalization exercises. The pressure is read by a wireless sensor connected to a smartphone, and the data can be saved and analyzed with the dedicated app.

With the EarOn app you can check how each maneuver is performed, from the basic techniques to the advanced ones, and save your training sessions. Freedivers can practice all the equalization techniques: Frenzel, Advanced Frenzel, Sequential Frenzel and Mouthfill.

Water pipe

The water pipe is an analog device designed to improve equalization skills: it measures the pressure in the nasal cavity during the equalization exercises.

With the water pipe freedivers can practice all the equalization techniques: Frenzel, Advanced Frenzel, Sequential Frenzel and Mouthfill.