Can the device be used by a 5-year-old child who has not started to speak yet?

Our device is a generator that emits the Schumann frequency in the form of infrared radiation and it acts on the energy balance, homeostasis and the overall body-spiritual balance of our organism, raising our immunity to satisfactory limits, and preventively acting on many conditions that can be the cause of various types of disorders in our organism. It can also be used by children. We still have no experience with how it specifically affects the appearance of delayed speech in children, and any feedback would be valuable to us. What is certain is that it cannot be harmful, and it would be used normally by placing it in the projection of the solar plexus at the level on the top of the sternum, which would achieve an effect on the entire organism (3-4 times a day for half an hour).