Frenzel equalisation using an EQ tool; A step-by-step guide

The frenzel manouever is named after a German doctor Hermann Frenzel and was developed in 1938 to be thought to dive bomber pilots during the World War 2. The manoeuvre is used to equalise the middle ear and today is performed by both SCUBA and freedivers.

Why do we need to equalise?

Boyles law states that ‘At a fixed temperature, the volume of a gas is inversely proportional to the pressure exerted on that gas’. Our body tissue is made of water which is non compressible. However, gases are compressible so freediving has an effect on the airspaces in our body. This is why as we descend, the volume of the air inside our middle ear decreases and we feel an introflection (bending inwards) of the ear drum and this is why we have to equalise. We are compensating for a reduction in volume in the middle ear caused by an increase in pressure.

How is the frenzel manoeuvre performed?

Frenzel equalisation involves creating pressure both in the oral and nasal cavities against pinched nostrils, sending air into the middle ear. It is the most efficient and relaxed way to equalise.

The diagram above shows all the airspaces (apart from the lungs) as well as the doors, that need to be moved to create pressure and shift air into the middle ear. If you want to know more about these airspaces and doors, we go into detail over here.

Air can not only be shifted or compressed by the tongue (which is the most common way thought) during frenzel, but also by the cheeks or the jaw. This gives beginners an opportunity to use different parts of the mouth to compress air, as not everyone has the proper motor coordination of the tongue. In this blog I’ll be showing you how to; tongue frenzel, jaw frenzel & cheek frenzel, which essentially when used all together is mouthfill.

Think of the exercises below as a chain. Each exercise should be performed until it’s very close to perfect. If another exercise is attempted before the previous one is learnt, the link is broken and you will not progress.

Basis skills

In these first three exercises, we will be focusing on managing the glottis and tongue, which is essential for all the following exercises. You will need a mirror to see what’s going on and to correct yourself.

Glottis control

The objectives of this exercise is to become aware of the glottis in the empty lungs condtition and to keep it closed after an active exhalation.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Open your mouth, wide open
  3. Perform an active exhalation
  4. Close the glottis by moving the diaphragm upward into the chest
  5. Feel the negative pressure in your lungs
  6. Open the glottis and feel the air being pulled in
  7. Repeat until it becomes easy

The exercise is correct is you can see the uvula at the back of the mouth, the first breathing action after opening the glottis is an inhalation and you can feel a vacum in your clavicles

Exercise value: To perform frenzel or mouth-fill, the glottis must be closed. Many exercises with the EQ require the glottis to be closed.

Tongue coordination – Glottis open

The objective of this exercise is to become conscious of where the tongue is located during a natural gesture such as breathing in and out, whilst improving movements of the rear part of the tongue

How to perform the exercise

  1. Look at yourself in the mirror
  2. Open your mouth, wide open
  3. Put the tip of your tongue behind inferior incisors
  4. Place your index finger on the adams apple to feel the movement
  5. Inhale only from the mouth and produce an ‘AAAAAA’ sound (just like going to the doctor) and lower the back part of the tongue down as much as possible
  6. Exhale through the nose and become aware of the tongue raising up against the palate (Also know as the K-lock)
  7. Repeat until it becomes easy

The exercise is correct if the tip of the tongue remains behind the inferior incisors whilst always being able to see the uvula when lowering the tongue. When the tongue goes up, you cannot see the uvula.

Exercise value: Improving co-ordination of the tongue is essential for the mouthfill, compressing air as well as moving through all the locks.

Tongue coordination – Glottis closed

The objective of this exercise is to move the tongue autonomously, whilst optimising the vertical rise and fall of the rear part of the tongue, whilst keeping the glottis closed.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Open your mouth, wide open
  3. Perform the Glottis control exercise
  4. Place your index finger on the adams apple to feel the movement
  5. Lower the rear part of the tongue, making sure uvula is visible
  6. Raise the rear part of the tongue, covering the uvula
  7. Repeat until it becomes easy

The exercise is correct if the tip of the tongue remains behind the inferior incisors. When lowering and raising the tongue, the uvula must appear and disappear. At the end of the exercise, when you open your glottis, the first breathing action is inhaling.

Exercise value: Improving co-ordination of the tongue is essential for the mouthfill, compressing air as well as moving through all the locks.

Mouth as a pump system

Now that we have the correct tongue movement, it’s time to start working on the cheeks and the jaw. In the next three exercises, we are going to learn how the mouth is a pump that allows us to perform frenzel by pushing the air out from the mouth to the outer environment. You will need a mirror and a straw (or Ottovent/ EQ tool)

Jaw compression

The objectives of this exercises is to isolate the upward and downward movement of the jaw necessary to push the air out whilst having the glottis closed.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Exhale and close the glottis
  3. Act out like you are giving a kiss
  4. Open and close the jaw. If you don’t feel the air moving, use a straw
  5. Repeat 15 times
  6. open the glottis and inhale
  7. Repeat until it becomes easy

The exercise is correct if the Adam’s apple remains still and down, indicating the tongue is not moving. The lips should remain slightly open for air to move freely.

Tongue compression

The objectives of this exercises is to isolate the motor control of the tongue necessary to push the air out whilst having the glottis closed.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Exhale and close the glottis
  3. Act out like you are giving a kiss
  4. Lower and raise the back of the tongue, feeling the air come in and out of the mouth.
  5. Repeat 15 times
  6. open the glottis and inhale
  7. Repeat until it becomes easy

The exercise is correct if the Adam’s apple makes large vertical movements, without the jaw moving ensuring the lips remain slightly open for air to move in and out.

Cheeks compression

The objectives of this exercises is to isolate the motor control of the cheeks necessary to push the air out whilst having the glottis closed.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Exhale and close the glottis
  3. Open your jaw and let the ambient air fill your mouth.
  4. Close your jaw, keeping your lips tight and allowing the cheeks to fill
  5. Squeeze your cheeks together starting from the front part and feel the air being compressed allowing the air to escape.
  6. Repeat 15 times
  7. Open the glottis and inhale
  8. Repeat until it becomes easy

The exercise is correct if the jaw and Adam’s apple remain still whilst during compression, the lips slightly open to push the air out.

Glottis control – adding stress

The next three exercises will be the same as the previous three, however with an added stress using the Ottovent or EQ tool and a balloon, creating pressure against the Glottis.

Jaw compression

The objectives of this exercises is to isolate the upward and downward movement of the jaw, and manage to push the air out of the mouth and into the balloon. Learn to feel and control the overpressure created by the EQ tool.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Inflate the balloon and remove it from your mouth
  3. Exhale and close the glottis
  4. Place the EQ tool in your mouth
  5. Allow the over pressure to fill up the cheeks, open the jaw and keep the tongue down.
  6. Open and close the jaw, feeling the compression of the air from the mouth to the balloon and vice versa.
  7. Repeat 15 times
  8. Open the glottis and inhale
  9. Repeat until it becomes easy

The exercise is correct if the Adam’s apple remains still and down, indicating the tongue is not moving. The cheeks and the under-chin should remain swollen.

Tongue compression

The objectives of this exercises is to isolate the motor control of the tongue and manage to push the air out of the mouth and into the balloon. Learn to feel and control the overpressure created by the EQ tool.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Inflate the balloon and remove it from your mouth
  3. Exhale and close the glottis
  4. Place the EQ tool in your mouth
  5. Allow the over pressure to fill up the cheeks, open the jaw and keep the tongue down.
  6. Lower and raise the back of the tongue, feeling the air come in and out of the mouth.
  7. Repeat 15 times
  8. open the glottis and inhale
  9. Repeat until it becomes easy

The exercise is correct if during compression, the Adam’s apple makes large vertical movements and the under chin becomes flat whilst the jaw remains still. Cheeks should remain swollen.

Cheeks compression

The objectives of this exercises is to isolate the motor control of the cheeks and manage to push the air out of the mouth and into the balloon. Learn to feel and control the overpressure created by the EQ tool.

How to perform the exercise

  1. Look at yourself in the mirror
  2. Exhale and close the glottis
  3. Place the EQ tool in your mouth
  4. Allow the over pressure to fill up the cheeks, open the jaw and keep the tongue down.
  5. Squeeze your cheeks together starting from the front part and feel the air being compressed allowing the air to escape into the balloon
  6. Repeat 15 times
  7. Open the glottis and inhale
  8. Repeat until it becomes easy

The exercise is correct if the Adam’s apple and jaw remains still.

Equalisation awareness exercises for the soft pallet and Glottis

Phonetics is a powerful way to build a bridge between the oral and nasal cavities, whilst managing to feel both airspaces as one. By using the locks at the mouth level and pronouncing consonants such as ‘P’ or ‘T’, we are able to control the soft pallet and feel the air filling up the mouth. The three locks are ‘P lock’, ‘T lock’ and ‘K lock’. In the diagram below, we have the locks on the vertical axis against the oral and nasal sounds on the horizontal axis.

B charge using the P lock

The objectives are to become aware how the ‘B’ sound is formed with the ‘P’ lock whilst the air is being pushed from the lungs to the mouth with the soft palate closed. Become aware of how the ‘B’ charge charges the mouth.

How to perform the exercise

  1. Look at yourself in the mirror for evaluation
  2. Pronounce the B sound
  3. Feel the air fill up your mouth. Try to go slow and relax as much as possible. Let the air fill your mouth without forcing.
  4. Hold the charge for a few seconds
  5. Repeat until easy

The exercise is correct if the cheeks are swollen, the rear part of the tongue is down (refer to Adam’s apple), the under chin is swollen and the jaw dropped (without opening the mouth)

Exercise value: To learn how to fill all the airspaces in the mouth, keeping the soft pallet closed

M charge using the P lock

The objectives are to become aware how the ‘M’ sound is formed with the ‘P’ lock whilst the air is being pushed from the lungs to the mouth with the soft palate open. Become aware of how the ‘M’ charge charges the mouth and connects the nasal cavity.

How to perform the exercise

  1. Look at yourself in the mirror for evaluation
  2. Pronounce the M sound
  3. Whilst pronouncing, nothing happens because the air comes out of the nose.
  4. Pinch your nose and start to feel the air filling both air spaces.
  5. Feel the air storage in the mouth and nasal cavity
  6. Hold the charge for a few seconds
  7. Repeat until easy

The exercise is correct if the cheeks are swollen, the rear part of the tongue is down (refer to Adam’s apple), the under chin is swollen and the jaw dropped (without opening the mouth)

Exercise value: To learn how to fill all the airspaces in the mouth, keeping the soft pallet open

D charge using the T lock

The objectives are to become aware how the ‘D’ sound is formed with the ‘T’ lock whilst the air is being pushed from the lungs to the mouth with the soft palate closed. Become aware of how the ‘D’ charge charges the airspace behind the tongue.

How to perform the exercise

  1. Look at yourself in the mirror for evaluation
  2. Pronounce the D sound
  3. Whilst pronouncing, feel the air charging the airspace behind the tongue
  4. Once the airspace is full, the phonation naturally stops
  5. Hold the charge for a few seconds
  6. Repeat until easy

The exercise is correct if the airspace behind the tongue is filling up. The cheeks should be empty whilst the tip of the tongue is behind the front teeth. The under chin should be swollen and the jaw should stay still.

N charge using the T lock

The objectives are to become aware how the ‘N’ sound is formed with the ‘T’ lock whilst the air is being pushed from the lungs to the mouth with the soft palate open. Become aware of how the ‘N’ charge charges the mouth and connects the nasal cavity.

  • Look at yourself in the mirror for evaluation
  • Pronounce N as if you were saying ‘Night’
  • Whilst pronouncing, nothing happens because the air comes out of the nose.
  • Pinch your nose and start to feel the air filling the airspace behind the tongue
  • Once the airspace is full, the phonation naturally stops
  • Hold the charge for a few seconds
  • Repeat until easy

Exercise value: To learn how to fill all the airspaces behind the tongue, keeping the soft pallet open. Learn how to take a charge and equalise to depth.

Frenzel technique by use of the Ottovent / EQ tool

Finally, this is where the magic happens and all that we’ve learnt comes together. Mastering the frenzel technique by use of the Eq tool / Ottovent is essential to deep diving. Whilst the Valsava technique can work, it’s the most inefficient and the frenzel technique will get you to the bottom both with speed and comfort.

Before we move onto the three types of Frenzel manoeuvres, we’ll first learn to understand how it feels to recharge air into the mouth by removing locks. This is the first time we will be creating an overpressure in the nasal cavity with the EQ tool / Ottovent

Fractional removal M (P lock)

The objectives are to feel the over pressure in the nasal cavity and mouth with the P lock. You will learn to remove and restore the P lock without moving other structures.

How to perform the exericse

  1. Look at yourself in the mirror and observe yourself
  2. Inflate the Ottovent, exhale and close the glottis
  3. Place the Ottovent / EQ tool in one nostril and close the other, letting the air fill the mouth and nasal cavity.
  4. Relax the mouth as much as possible and let the air fill all the airspaces
  5. Remove the P lock and feel the air come out
  6. Restore the P lock, again letting the air fill the spaces
  7. Repeat until easy

The exercise is correct if the cheeks are swollen, rear part of the tongue is down and the under chin is swollen. Air should escape from the mouth.

Fractional removal N (T lock)

The objectives are to feel the over pressure in the nasal cavity and mouth with the T lock. You will learn to remove and restore the T lock without moving other structures.

How to perform the exericse

  1. Look at yourself in the mirror and observe yourself
  2. Inflate the Ottovent, exhale and close the glottis
  3. Place the Ottovent / EQ tool in one nostril and close the other, letting the air fill the mouth and nasal cavity.
  4. Feel the relaxation of the rear part of the tongue and lowering of the Adam’s apple
  5. Remove the T lock and feel the air come out
  6. Restore the T lock, again letting the air fill the spaces
  7. Lower rear part of the tongue and notice the under chin swelling
  8. Repeat until easy

Jaw Frenzel

The objectives are to acquire sensations and control the jaw frenzel technique compressing the air only with the jaw, whilst isolating the movement from the cheeks and tongue.

How to perform the exericse

  1. Look at yourself in the mirror and observe yourself
  2. Inflate the Ottovent, exhale and close the glottis
  3. Place the Ottovent / EQ tool in one nostril and close the other, letting the air fill the mouth and nasal cavity.
  4. Close and open the jaw and feel the air being compressed from the mouth to the Ottovent and vice versa
  5. Repeat 10 times
  6. Remove the EQ tool and open the glottis
  7. Repeat until easy

Cheeks Frenzel

The objectives are to acquire sensations and control the cheek frenzel technique compressing the air only with the cheeks, whilst isolating the movement from the jaw and tongue.

How to perform the exericse

  1. Look at yourself in the mirror and observe yourself
  2. Inflate the Ottovent, exhale and close the glottis
  3. Place the Ottovent / EQ tool in one nostril and close the other, letting the air fill the mouth and nasal cavity.
  4. Compress the cheeks and feel the air being compressed from the mouth to the Ottovent and vice versa
  5. Repeat 10 times
  6. Remove the EQ tool and open the glottis
  7. Repeat until easy

Tongue Frenzel

The objectives are to acquire sensations and control thetongue frenzel technique compressing the air only with the tongue, whilst isolating the movement from the cheeks and jaw.

How to perform the exericse

  1. Look at yourself in the mirror and observe yourself
  2. Inflate the Ottovent, exhale and close the glottis
  3. Place the Ottovent / EQ tool in one nostril and close the other, letting the air fill the mouth and nasal cavity.
  4. Raise the rear part of the tongue and feel the air being compressed from the mouth to the Ottovent and vice versa when lowering the tongue again
  5. Repeat 10 times
  6. Remove the EQ tool and open the glottis
  7. Repeat until easy

Comclusion

Learning the freznel equalisation technique is essential to both recreational and professional freedivers alike. Always remember each skill is a link which needs to be strengthened by repetition and consistency. Once you are confident and strong in one skill, move onto the next. This is not the only method in learning the frenzel technique, however if you want to fine tune and perfect it then this is the way to go. This is all thanks to Federico Mana who was my teacher and guide during my equalisation instructor course. If you’d like to know more about him, get in touch here and if you need any guidance then get in touch with me.