It is designed to reduce stress and lower bloodpressure. Your practitioner will then explain. With practice, it is possible to make the same bodily changes that the practitioner suggests without having to use the feedback screen. Biofeedback may help incontinence sufferers reduce their urgency to urinate, as well as the number and severity of their accidents. Researchers are not sure exactly how or why biofeedback works. Healthy adults should be capable of hearing frequencies from 20 to 20.000 Hz. These can be attached to the machine that produces electrical impulses. Further reporting claims that Rife machines have been "unanimously condemned by mainstream scientists as worthless and banned in at most two American States."