You can sing them out loud, and it is also possible to just „think“ them or sing them internally.
They are able to inform every other layer of your system including emotional, mental and spiritual bodies. They work for humans as well as animals, especially mammals. They are powerful instruments of self-healing – and as I said before, you do not need to be a singer to use them, because you do not need to sing them out loud.
Most of the problems you see in humans and animals are multidimensional; similar to the way mainstream medicine talks about psychosomatic diseases. Soundcodes are able to work on all levels at the same time. That seems to be an extraordinary factor and one that is not present in most healing modalities.
At the same time they are safe, because no physical manipulation is occuring through the Soundcodes. The body decides all by itself, how, when and in which capacity it will receive and use the given information.