Understanding Equalization: The Anatomy of the Ear and Sinuses for Freediving

08 May 2023

UNDERSTANDING EQUALIZATION

Apnea Addicts Freediving School

Freediving - Understanding Equalization

Equalization... Understand the Process

Freediving is an exhilarating experience that involves diving deep underwater without the use of any breathing apparatus. However, as with any activity, it requires proper technique, training, and equipment, safety is paramount and one of the most important aspects of safe freediving is equalization. Equalization is the process of balancing the pressure between the environment and the body’s airspaces, which include the ears and sinuses. Equalization is necessary to prevent barotrauma, which is a condition that occurs when the pressure difference causes damage to the ear or sinuses. In this article, we will explore the anatomy of the ear and sinuses and how it relates to equalization during freediving.

KeatZA
KeatZA
Brilliant instructors. The Apnea Addicts team look after you through the entire process and ensure that you are comfortable in the water and understand the fundamentals of the sport.
Reece Truter
Reece Truter
One of the best experiences I have had with a dive shop. I was blown away by how beautiful the African Sea Forest was and had many amazing dives from shore entry and off a boat all during my freediving course and improving my skills, reaching new depths and learning how to do it all safely.
Amber McLeod
Amber McLeod
Charl and Brit are amazing instructors :) Doing my freediving instructor course with them. Super patient people and they have very adaptable teaching styles that will suit anyone. Very fun course!
Leroux Cloete
Leroux Cloete
Best in the business, took my free diving to the next level and will recommend it to anyone looking to dive safer and improve their diving.
YB Naidoo
YB Naidoo
Gareth did such an amazing job with Mischka, he reads people extremely accurately and helps them accordingly. I seriously recommend Gareth and his team if you value patience and understanding. Thanks for the breathtaking experience guys, well done!
Boy de Jonge
Boy de Jonge
Did my 4 day Open Water Course, both Gareth and Indi are very nice, highly qualified and know where to go for the best Cape Town dive spots. Highly recommend!
Jonathan Müller
Jonathan Müller
Great communication. Great instructor. My son loved it.

Paradise42498870172
Paradise42498870172
2023-11-09
Amazing diving and skill improving. I had such an amazing time in Cape Town while being shown around with Apnea Addicts Freediving. We visited many dive sites via shore and boat. All while improving my diving skills on freediving courses.
GoPlaces67263033124
GoPlaces67263033124
2023-11-07
Amazing Charl and Brit are amazing instructors :) Doing my freediving instructor course with them and they have very adaptable teaching styles that will suit anyone. Very fun course!
Passport38210741530
Passport38210741530
2023-11-07
Spear fishing trip Beautiful waters and friendly cow sharks + friendly charles. Will recommend this to anyone. Gona come back again for sure.
Leroux C
Leroux C
2023-11-07
If you are a free diver this is a must!!! Best in the business, took my free diving to the next level and will recommend it to anyone looking to dive safer and improve their diving.
Hayley C
Hayley C
2021-05-13
Amazing shore dives with great people! I was recommended this dive shop by a local and it was the best choice I could have made! It’s a small company, so you get an intimate, personalized experience. Joe was a fantastic coordinator and extremely knowledgeable about the sites and marine life. Philippe was my dive buddy and helped me feel really comfortable and took great care of me on our dives. We saw incredible kelp forests, beautiful coral, nudibranchs of many kinds, swam through rock formations, and a friendly seal even came by and gave us a quick show. I’m so glad I chose to dive in SA, and I’m even happier I picked Cape Town Dive Centre. Thank you Joe and Philippe!!
Tarryn B
Tarryn B
2021-05-07
PADI Open Water & Advanced Open Water courses - an unforgettable experience When I finally decided that it was time to learn to scuba dive (something I’d wanted to do for years), I signed up for the Open Water Course with the Cape Town Dive Centre because of a friend's recommendation. From the minute the Open Water Course started, I loved everything about it! My instructor, Joe, was fun but also incredibly efficient and an excellent teacher. The course was quite difficult and complex so I wouldn't have wanted to do it with just anyone. However, because of the way Joe taught and helped us under the water, I felt totally safe and calm. By the end of the course I was totally hooked on scuba diving! So much so, in fact, that a couple of months later I returned to the Cape Town Dive Centre to do my Advanced Open Water Course. For anyone who intends on continuing to scuba dive after completing the Open Water Course, I would strongly recommend doing the Advanced Open Water Course too. This course really expanded my knowledge and improved my capabilities, ultimately making me a much more competent and confident diver – with much improved buoyancy and air consumption as an added bonus! So, if the above isn't already clear, let me say this: I would highly recommend going to the Cape Town Dive Centre to start and/or continue your diving journey! All of the staff are friendly and super well qualified, and will go out of their way to accommodate you and any concerns you may have. You are bound to have a phenomenal experience – in the water and out of it!
Claude Visagie
Claude Visagie
2021-04-10
First scuba dive What an amazing experience. Friendly instructors that are extremely knowledgeable and helpful. Would recommend this to anyone visiting Cape Town and to all the locals!!
Andrew Scott
Andrew Scott
2021-03-09
PADI open water diver course Just completed a PADI open water diving course with Cape Town Dive Centre. Was an amazing experience and loved every minute of it! Staff very professional and drilled us on every important aspect of the course. Great value for money and can really recommend it to anyone wanting to get into SCUBA
BoardingPass760957
BoardingPass760957
2021-02-08
You haven't lived if you haven't tried scuba diving! Our diving instructor Joe was already waiting for us with our gear when we arrived, which was great. He was very patient and helpful and made 200% sure we had all the basic skills mastered. I couldn't complete my dive, but he continued with my son, who is now totally hooked on scuba diving. I'm giving the experience 4 out of 5 as it was too short, a 4-hour experience was advertised and it was under 2-hours from arriving to leaving (trying to get into the wet suits and the instructions was about an hour). I can wholeheartedly recommend this and trust me, you are in SAVE hands with these people, they know what they are doing and know how to handle emergencies. Thank you, Joe!
bhbruwer
bhbruwer
2020-11-07
Great Experience! Great experience with friendly staff that makes you feel at ease throughout the dive. Will definitely recommend CTDC! Thanks Gareth!

FREEDIVING

Freediving is a form of underwater diving that relies on the diver’s ability to hold their breath, rather than using a breathing apparatus such as scuba gear. Freedivers may use fins and other diving equipment to help them swim deeper and faster, but they do not carry air tanks or use regulators to breathe while underwater.

Understanding Equalization of the Ear

The key to understanding equalization, it’s essential to know the anatomy of the ear and sinuses. The ear is a complex and delicate organ that plays a critical role in hearing and balance. The ear is divided into three parts: the outer ear, the middle ear, and the inner ear. The outer ear consists of the pinna (the visible part of the ear) and the ear canal (the part that fills with water when you bath/swim/surf), which leads to the eardrum. The middle ear is an air-filled chamber that contains three small bones (the ossicles) that vibrate in response to sound waves. The inner ear is a complex structure that includes the cochlea (the organ of hearing) and the semicircular canals (which help with balance).

 

The sinuses are air-filled cavities within the skull that connect to the nasal passages. There are four pairs of sinuses: the maxillary sinuses (in the cheekbones), the frontal sinuses (above the eyebrows), the ethmoid sinuses (between the eyes), and the sphenoid sinuses (behind the nose). The sinuses are lined with mucous membranes that produce mucus to moisten and protect the nasal passages.

 

During freediving, as the pressure increases with depth, the air spaces in the ear and sinuses become compressed. The pressure in the middle ear will then become unequal due to the change in pressure as one descends into the water. This can cause discomfort and even damage to the ear if not properly equalized. Equalization is achieved by allowing air to flow from the nasopharynx (the back of the nasal passages) into the middle ear via the Eustachian tube. The most common technique for equalizing the middle ear during freediving is the Frenzel Maneuver. Understanding Equalization, especially the Frenzel technique is of importance to deep diving.

Understanding Frenzel Equalization

There are different methods of equalization, but understanding equalization in all methods is not of consequence, the most common technique used by freedivers is the Frenzel maneuver. The Frenzel maneuver involves closing the glottis (the opening between the vocal cords) and using the muscles in the back of the throat to force air from the lungs into the nasopharynx. The air then flows into the middle ear, equalizing the pressure. This means by using the muscles in the throat to push air into the middle ear, equalizing the pressure. The Eustachian tube is a narrow passage that connects the middle ear to the back of the nose and throat. The Frenzel maneuver is the preferred technique for equalizing the middle ear during freediving because it requires less air than other techniques, and is more controlled.

 

To perform the Frenzel maneuver, one must first take a deep breath and hold it. Then, the back of the tongue is pressed against the roof of the mouth while simultaneously contracting the muscles in the throat. This creates pressure in the back of the nose and throat, which forces air through the Eustachian tube and into the middle ear, equalizing the pressure.

 

Freedivers should start equalizing early and frequently during a dive. As a general rule, it’s recommended to equalize every meter of descent or every two to three seconds. It is important to note that equalization should be done more often first few meters of descent. This ensures that the pressure in the ears is equalized before any discomfort or damage can occur.

 

Here is a link that explains Frenzel Equalisation well: https://www.youtube.com/watch?v=Mo07gZR741M

Understanding Valsalva Equalization

The Valsalva maneuver is a technique that involves closing the mouth and nose and exhaling against a closed airway. This creates pressure in the chest, which pushes air into the sinuses, equalizing the pressure. This is the first and most common way of equalization. However, the Valsalva maneuver can put a significant amount of pressure on the inner ear and should be used with caution during freediving.

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The Sinuses - Understanding Equalization

Understanding equalization of the sinuses is important, and very often quite underrated. The sinuses are air-filled cavities that are located within the bones of the face and skull. They are lined with a thin layer of tissue called the mucous membrane, which produces mucus to keep the sinuses moist and healthy. The sinuses play an important role in the respiratory system by helping to filter, warm, and humidify the air we breathe. Additionally, they also help to reduce the weight of the skull, making it easier to move the head.

 

There are several different types of sinuses, including the maxillary sinuses (located in the cheeks), the frontal sinuses (located in the forehead), the ethmoid sinuses (located between the eyes), and the sphenoid sinuses (located in the center of the skull). Each sinus is connected to the nasal passages by a small opening called an ostium.

 

During freediving, the pressure changes that occur can affect the sinuses and cause discomfort or even injury if proper equalization is not performed. It is important to note that at shallow depths, such as those typically encountered at the PADI Freediver level, either form of equalization (Valsalva or Frenzel) would be sufficient to equalize the sinuses and ears. However, at deeper depths, the pressure changes can become more significant, and a more advanced equalization technique such as the Mouthfill may be necessary to properly equalize the sinuses and avoid discomfort or injury.

 

It is also worth noting that sinus issues, such as congestion or infection, can make equalization more difficult and potentially more dangerous during a dive. Divers should always ensure that their sinuses are clear and healthy before attempting any kind of freediving and should seek medical attention if they experience any sinus-related issues before or after a dive.

Understanding the Repercussions of Improper Equalization

Proper equalization is critical for safe and enjoyable freediving. Understanding the anatomy of the ear and sinuses can help freedivers master the techniques required to equalize effectively. By starting early and frequently equalizing, listening to your body, and using the Frenzel maneuver, you can prevent barotrauma and enjoy the wonders of the underwater world.

 

Failing to properly equalize can lead to discomfort, pain, and even injury. Barotrauma is a common injury that can occur when air spaces are not properly equalized. This can cause pain, discomfort, and damage to the delicate structures of the ear.

 

Another potential complication of improper equalization is sinus barotrauma. This occurs when there is an imbalance in pressure between the sinuses and the surrounding environment, leading to pain and swelling in the affected area. In some cases, it can lead to sinus infections or even permanent damage to the sinuses. Repeated improper equalization can also lead to long-term damage to the inner ear, including the development of otosclerosis and other forms of hearing loss.

 

While it is important to take equalization seriously, don’t let the possible complications discourage you from freediving. With proper technique and awareness, the risk of injury can be greatly reduced. It’s essential to equalize early and often, using the appropriate techniques to ensure proper pressure release and avoid barotrauma. In case of any discomfort or pain during equalization, it’s best to stop and ascend slowly while continuing to equalize. Remember, proper equalization enhances your overall freediving experience, making it comfortable and enjoyable.

References

Fagoni N, Taboni A, Tam E, et al. Cardiovascular changes during apnea in elite divers. J Sports Sci. 2015;33(5):487-497.

Ferretti G, Costa M, Domenici L. Cardiovascular response to diving in humans and marine mammals. In: Melatonin, Neuroprotective Agents and Antidepressant Therapy. Springer; 2016:265-288.

Lindholm P, Lundgren CEG. Alveolar gas composition before and after maximal breath-holds in competitive divers. Undersea Hyperb Med. 2006;33(1):39-44.

Marlinge M, Pesce C, Mallié JP, et al. Cardiovascular and thoracic blood volume changes during voluntary static and dynamic apnea. Int J Sports Med. 2004;25(2):116-121.

Møllerløkken A, Berge HM, Gutvik CR, et al. Cardiovascular and respiratory responses to apneas with and without face immersion in exercising humans. J Appl Physiol. 2016;121(1):201-208.

Schipke JD, Pelzer AT, Heinrich T, et al. Cardiovascular and cerebrovascular response to graded apnea in healthy humans. Respir Physiol Neurobiol. 2013;187(1):58-65.

Schipke JD, Gams E, Kallusky J, et al. Cardiovascular effects of apnea diving in healthy humans. Am J Cardiol. 2015;115(4):530-534.

 

West J, Schoene RB, Milledge JS, Ward MP. High Altitude Medicine and Physiology. CRC Press; 2012.

Apnea

Apnea is the temporary suspension of breathing. In the context of freediving, apnea refers to the act of holding one’s breath while underwater. Freedivers often practice apnea in order to increase their ability to hold their breath and to dive to deeper depths.

Understanding Equalization
Understanding Equalization

KeatZA
KeatZA
Brilliant instructors. The Apnea Addicts team look after you through the entire process and ensure that you are comfortable in the water and understand the fundamentals of the sport.
Reece Truter
Reece Truter
One of the best experiences I have had with a dive shop. I was blown away by how beautiful the African Sea Forest was and had many amazing dives from shore entry and off a boat all during my freediving course and improving my skills, reaching new depths and learning how to do it all safely.
Amber McLeod
Amber McLeod
Charl and Brit are amazing instructors :) Doing my freediving instructor course with them. Super patient people and they have very adaptable teaching styles that will suit anyone. Very fun course!
Leroux Cloete
Leroux Cloete
Best in the business, took my free diving to the next level and will recommend it to anyone looking to dive safer and improve their diving.
YB Naidoo
YB Naidoo
Gareth did such an amazing job with Mischka, he reads people extremely accurately and helps them accordingly. I seriously recommend Gareth and his team if you value patience and understanding. Thanks for the breathtaking experience guys, well done!
Boy de Jonge
Boy de Jonge
Did my 4 day Open Water Course, both Gareth and Indi are very nice, highly qualified and know where to go for the best Cape Town dive spots. Highly recommend!
Jonathan Müller
Jonathan Müller
Great communication. Great instructor. My son loved it.

Paradise42498870172
Paradise42498870172
2023-11-09
Amazing diving and skill improving. I had such an amazing time in Cape Town while being shown around with Apnea Addicts Freediving. We visited many dive sites via shore and boat. All while improving my diving skills on freediving courses.
GoPlaces67263033124
GoPlaces67263033124
2023-11-07
Amazing Charl and Brit are amazing instructors :) Doing my freediving instructor course with them and they have very adaptable teaching styles that will suit anyone. Very fun course!
Passport38210741530
Passport38210741530
2023-11-07
Spear fishing trip Beautiful waters and friendly cow sharks + friendly charles. Will recommend this to anyone. Gona come back again for sure.
Leroux C
Leroux C
2023-11-07
If you are a free diver this is a must!!! Best in the business, took my free diving to the next level and will recommend it to anyone looking to dive safer and improve their diving.
Hayley C
Hayley C
2021-05-13
Amazing shore dives with great people! I was recommended this dive shop by a local and it was the best choice I could have made! It’s a small company, so you get an intimate, personalized experience. Joe was a fantastic coordinator and extremely knowledgeable about the sites and marine life. Philippe was my dive buddy and helped me feel really comfortable and took great care of me on our dives. We saw incredible kelp forests, beautiful coral, nudibranchs of many kinds, swam through rock formations, and a friendly seal even came by and gave us a quick show. I’m so glad I chose to dive in SA, and I’m even happier I picked Cape Town Dive Centre. Thank you Joe and Philippe!!
Tarryn B
Tarryn B
2021-05-07
PADI Open Water & Advanced Open Water courses - an unforgettable experience When I finally decided that it was time to learn to scuba dive (something I’d wanted to do for years), I signed up for the Open Water Course with the Cape Town Dive Centre because of a friend's recommendation. From the minute the Open Water Course started, I loved everything about it! My instructor, Joe, was fun but also incredibly efficient and an excellent teacher. The course was quite difficult and complex so I wouldn't have wanted to do it with just anyone. However, because of the way Joe taught and helped us under the water, I felt totally safe and calm. By the end of the course I was totally hooked on scuba diving! So much so, in fact, that a couple of months later I returned to the Cape Town Dive Centre to do my Advanced Open Water Course. For anyone who intends on continuing to scuba dive after completing the Open Water Course, I would strongly recommend doing the Advanced Open Water Course too. This course really expanded my knowledge and improved my capabilities, ultimately making me a much more competent and confident diver – with much improved buoyancy and air consumption as an added bonus! So, if the above isn't already clear, let me say this: I would highly recommend going to the Cape Town Dive Centre to start and/or continue your diving journey! All of the staff are friendly and super well qualified, and will go out of their way to accommodate you and any concerns you may have. You are bound to have a phenomenal experience – in the water and out of it!
Claude Visagie
Claude Visagie
2021-04-10
First scuba dive What an amazing experience. Friendly instructors that are extremely knowledgeable and helpful. Would recommend this to anyone visiting Cape Town and to all the locals!!
Andrew Scott
Andrew Scott
2021-03-09
PADI open water diver course Just completed a PADI open water diving course with Cape Town Dive Centre. Was an amazing experience and loved every minute of it! Staff very professional and drilled us on every important aspect of the course. Great value for money and can really recommend it to anyone wanting to get into SCUBA
BoardingPass760957
BoardingPass760957
2021-02-08
You haven't lived if you haven't tried scuba diving! Our diving instructor Joe was already waiting for us with our gear when we arrived, which was great. He was very patient and helpful and made 200% sure we had all the basic skills mastered. I couldn't complete my dive, but he continued with my son, who is now totally hooked on scuba diving. I'm giving the experience 4 out of 5 as it was too short, a 4-hour experience was advertised and it was under 2-hours from arriving to leaving (trying to get into the wet suits and the instructions was about an hour). I can wholeheartedly recommend this and trust me, you are in SAVE hands with these people, they know what they are doing and know how to handle emergencies. Thank you, Joe!
bhbruwer
bhbruwer
2020-11-07
Great Experience! Great experience with friendly staff that makes you feel at ease throughout the dive. Will definitely recommend CTDC! Thanks Gareth!

Want to know More?

Join the fun!

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