Frenzel Equalisation Explained

What Is Equalisation?

When we dive, pressure increases and affects any air-filled space in the body. Water doesn’t compress, but air does. As you go deeper, the air inside the middle ear gets squeezed and its volume drops. This causes the eardrum to be pulled inward, which is why we must equalise—adding air back into that space to match the pressure around us.

Why Equalisation Is Essential in Freediving

If you descend without adding air into the middle ear, pressure builds quickly and becomes painful. Ignoring this pressure can lead to ear barotrauma and other complications. When you equalise early and consistently, dives become comfortable, safe, and pain-free.

What Is the Frenzel Technique?

The Frenzel method uses the tongue and throat muscles to gently push air toward the middle ear. The glottis stays closed, trapping a small amount of air in the mouth and nasal passages. Using the back of the tongue, you compress that air and send it into the Eustachian tubes—resulting in the familiar “pop.”For this to work, the soft palate must remain in its neutral/open position so air can move freely.

Frenzel vs. Valsalva

Most new divers discover two equalisation styles early on: Frenzel and Valsalva.

Valsalva uses the diaphragm and chest muscles to force air upward from the lungs. This method is tiring, inefficient at depth, and relies on large muscle groups—making relaxation almost impossible. Over time, it simply stops working as pressure increases.

Frenzel is far more effective. It uses small, precise muscles in the tongue and throat, requires much less effort, and works reliably at any recreational depth. The distance air has to travel is much shorter, and the control is significantly better.

Anatomy Involved in Frenzel Equalisation

Glottis

The glottis is a “gate” between the mouth and lungs. Closing it traps air in the oral/nasal cavity. Because we can consciously open and close it, it’s considered a dynamic door.

Tongue

The tongue acts like a piston. It seals the air and compresses it upward toward the Eustachian tubes.

Soft Palate

This flexible tissue separates the mouth and nasal passages. For equalisation, it must stay open so air is free to pressurise both spaces. Because we can control its position, it’s also a dynamic door.

Eustachian Tubes

These narrow canals connect the middle ear to the throat. They normally stay closed and only open during certain movements—swallowing, yawning, or equalisation. Their job is to balance pressure across the eardrum.

Middle Ear

An air pocket behind the eardrum that shrinks quickly during descent. If it isn’t equalised early, the eardrum bends inward and can become painful or damaged.

Step-By-Step: How to Perform Frenzel

1. Pinch your noseThis traps air inside the system.

2. Close the glottisNo air should move to or from the lungs.

3. Seal the mouthNow the air in your oral/nasal cavity is isolated.

4. Set the tongue in a “T” or “K” position Find the one that feels more natural.

5. Use the back of the tongue to compress air upward Lift it gently toward the soft palate.

6. Feel the equalisation This small movement changes the volume in your mouth and directs air into the Eustachian tubes.

Exercises to Learn Frenzel

Glottis Awareness

• Exhale softly, then make a firm exhale and hold.• Keep the belly soft, neck relaxed, and chest lifted.• Look in the mirror—you’ll see a small dip in the throat when the glottis is sealed.• Release and notice the airflow returning.

Soft Palate Awareness

• Breathe slowly in and out through the nose with the mouth closed.• Focus your attention at the back of the throat.• Feel how the palate relaxes and “opens.”

Tongue Control

• Sit in front of a mirror with your mouth open.• Rest the tip of your tongue lightly behind your lower teeth.• Inhale through the mouth, exhale through the nose.• Notice how the tongue rises and falls—this is the movement used in Frenzel.

Common Issues in Equalisation

Difficulty Building Pressure

Often caused by an open glottis or not enough air in the mouth.

Struggling When Upside Down

The soft palate or glottis may unintentionally close. Proper technique and relaxation usually fix this.

Poor Frequency

You must equalise early and often. In the first 10 metres, air volume halves—this is the biggest pressure change of the dive.

Losing Air From the Mouth

As you go deeper, the oral cavity shrinks. Regain volume by dropping the tongue to pull air from the lungs (advanced “air-shift”).

Tension

Stress and poor relaxation tighten the throat muscles, making equalisation harder.

Asymmetrical Eustachian Tubes

One tube may open easier than the other. You may need slightly more pressure for the tighter side.

Incorrect Body Position

Tight shoulders, a lifted chin, or tension around the chest can all restrict the airways.

Over-Pressurising

Creating too much pressure can cause problems with the outer ear or even damage the Eustachian tubes.

Learning Challenges (Dry Training)

Trouble Closing the Glottis

A very common issue. Slow awareness exercises are the solution.

Difficulty Moving the Tongue or Vocal Folds

The motor control needs practice and patience.

Not Enough Air in the Oral Cavity

Without enough air to compress, Frenzel won't work.

Low Awareness

Understanding which muscles you are using takes time. With guidance, it improves quickly.

Dry Equalisation Tools

Working on equalisation out of the water removes pressure, stress, and breath-hold demands. Using EQ tools lets you increase difficulty slowly and safely, helping build precise muscle control before applying it to depth.

Contact Matt if you wish to complete a online equalisation workshop or training course.

More info here Online EQ