What "technically" happens when we chant Nam Myoho Renge Kyo?

I have been chanting Nam Myoho Renge Kyo (daimoku - Nichiren Daishonin's Buddhism) for about 4.5 years. I also regularly attend Soka Gakkai International (SGI) meetings. I have experienced a lot of benefits from the practice. But, I have been unable to understand what technically happens when we chant. I have read in some of the texts that we create a good karma when we chant or some of the questions here answered that the "act" of chanting leads us to the path of enlightenment. But, being a Physics student, I am interested in knowing what exactly happens when we chant. For example- when I chant, I generate sound energy. Now that energy would have some temporal variation as the words "Nam" , "Myoho" etc. would have different sounds but the ratio of amplitudes and frequencies would be almost equal for each person. I would be happy if someone can give a technical explanation of what exactly happens when we chant.