Almost all major health insurance cover the costs for Del Ferro completely. This is because they investigated the method themselves and could see that after years people still are stutter free. That's really unique for a health insure to cover 100% of the costs so that means something. But ok now back to science haha. I will give you the a some of literature from one of the most well known doctor ( at that time) called dr. Peter T Macklem. He was worlds leading expert on the diaphragm in the 80ts/90ts and he set up a big investigation where the role of the breathing muscles during stuttering were investigated in detail. See this major research study: [https://pubmed.ncbi.nlm.nih.gov/2350093/](https://pubmed.ncbi.nlm.nih.gov/2350093/) He states in this report that if the method results in getting a controlled psg back (which is the case) this would be strong evidence that the respiratory is the primary cause of stuttering. But you know, the most important is perhaps not the science but just the fact that I am cured and my fellow course mates of my group as well. So even if the method was not back up by science I would give it a try although I would be very skeptical of course. If I would be a scientist working in the field of stuttering I would really focus further on the rol of the diaphragm because I don't know any method world wide that achieves a completely 100% cure for stuttering for many of the people who followed the course. So if you would be a scientist today I would focus on trying to find out why these people (like me) can be cured for so long. I would set up my own study to find all these people in order to verify it. Its a bloody shame that this has NOT happend so far. How stupid can they be? I just that I want to best for everybody and it makes me angry because I know that a lot of people are suffering from stuttering and I know and have seen with my own eyes that a lot people do indeed never ever stutter anymore when the followed this method. It has been all over the TV in Germany, UK, en Holland. But if this method would not be in The Netherlands and I saw this information I would be very willing to give it a try. Ok, now your other point about 'belly' breathing. Well I can see you this: indeed you mist something revolutionary haha. Look, when those breathing coaches advice people to breath with the belly they always ask people to voluntary push their abs outside. The thing is that you don't activate and stretch your diaphragm this way, only for about 30%. How come? Because when you focus on your belly to push out then get a small vacuum because the organs go a bit to the front. Therefore the air comes in as a result of pushing your belly out because of the vacuum that you create. But this is not breathing from the diaphrag. People from the world of opera are often the only one who know this very well. Look, the diaphragm is striated muscle tissue and it connected to bones. That means that the muscle can be trained when you stretch it up. You won't achieve this with pushing your belly out because then you don't stretch and actively use the diaphragm. You breath with your ribs and not with the belly. The belly will always push out a bit that's true but you should really focus on the expansion of the lower rib case and training this ribcage and the intercostals so the ribs become more flexible (as in singing happens). But I can not say a lot more about how to achieve this because then I would sell their method which is not allowed. Its their own method which they teach to others in the course. They offer this unique training of the diaphragm and know precisely how to achieve this. Combined with psychological help and other ways people learn a speech technique that will make them stop stuttering. But in order to achieve this they need to use the method a small part of their life every single day, so that the brain, diaphragm and intercostals learn how to coordinate a steady flow of air with the diaphragm that gets used to this new steady and fluent movement which was not the case for all those years in which people had stuttering diaphragm. They have the tool and the knowledge and they keep proven that a lot of people get rid of their stammer once and for all if they are really motivated and prepared to work hard on training the diaphragm with their unique method which its no means a miracle cure but demands from people that they are prepared to follow op this method for a few months at least. ITs hard work but I I have seen so many people who's life turned around completely. Look on YouTube for example. This was my teacher by the way a very nice guy that is already more then 30 years cured of his stammer. You can hear them talk without a single stutter. [https://www.youtube.com/shorts/ktCtkc2FEc4](https://www.youtube.com/shorts/ktCtkc2FEc4) And this woman who was cured in her twenties and became a member of the Dutch parlement where she could use her voice in Dutch Politics. You can see it here: [https://www.youtube.com/watch?v=LXDKk4JbJeo](https://www.youtube.com/watch?v=LXDKk4JbJeo) Ok, I hope and really really wish that people can feel the way I feel now, let alone more then thousands of people worldwide who went to this famous institute from all over the world. Its not a 100% promise for a cure for everybody perse, I can simply not say this because a medicine for a certain disease can not work for everybody, how this can happen? I don't know. Therefor the research must continue to investigate further on this matter. But now it hurt my eyes if people say that stammering can not be cured. This is so untrue. They must say this on the website: "There are a lof people walking around that got rid of their stammer once and for all. They are cured. The hope is now that we can push the research forward in order to achieve a remission for as much people as possible. Its a message of hope! That's the thing I want people to give as a takeaway. :) A quick copy and paste from the website you find here below: **What is the Del Ferro Method?**The Del Ferro Method was developed in 1978 by Opera Singer Leonard del Ferro (1921-1992).As a singing teacher, Del Ferro was fascinated by the fact that stutterers who sing, do not stutter. After extensive research, he was able to develop an amazingly simple, yet effective method that has been scientifically verified in enabling people to overcome their stuttering problem.Over the last 40 years, the method has been developed to help people lose the fear of speaking and break free from the mental prison and social isolation that stuttering causes. Leonard’s daughter, Ingrid del Ferro, now runs the Del Ferro Institute and is carrying out her father’s legacy as she and her team continue to help change the lives of thousands of people.**The diaphragm**The method focusses on the diaphragm, a crucial muscle when it comes to our breathing and speaking. This muscle does not move smoothly during a stutter, causing disfluency in our speech. The unique Del Ferro Method ensures that the diaphragm moves smoothly and controlled, resulting in fluent speech.Motivation and a dedicated application of the Del Ferro Method will help your speech become and stay fluent. After a while, you will no longer need to do the Del Ferro exercises as you will be able to speak fluent in any situation, automatically. **Science-basedNeurologist Dr.J.C.J van Hemert** was the first to test Len del Ferro’s hypothesis in 1978. Neurologist Van Hemert’s scientific research shows, using X ray among other resources, that the diaphragm makes uncontrolled movements during stuttering. The air flow is severely disrupted, with the result that exhaled air passes by the vocal cords in fits and starts. Speaking with stutters is the result.Since then several times, scientifically, it’s concluded that The Del Ferro Method can solve stuttering effectively. Among neurologist Dr. M.P.A.M. de Grood (1915-1995) of the St. Elizabeth hospital, Tilburg. **Also professor Peter T. Macklem (1931-2011) of the McGill University in Montreal, Canada, one of the most renowned specialists in the field of lung physiology and the diaphragm, confirmed the conclusion of Del Ferro.**Under the leadership of Macklem thorough research is carried out for three years among the Erasmus hospital of the Free University in Brussels and in the Clinica Del Lavora in Pavia (Italy). He examined for instance the air pressure against the vocal cords, which is pressed by the diaphragm against the vocal cords. The conclusion was that when this air pressure/ stream is fluent, it’s impossible to stutter. The results of this research are published for instance in the well known scientific journal of the Thoracic society, shown below.Several health insurance companies have tested the effectiveness of The Del Ferro Method over the years. For the reason that the results turned out to be cost effective, health insurance companies moved over to reimbursement of this method.