Another technology designed to create specific body changes is biofeedback. Biofeedback is a non-invasive, painless, non-pharmaceutical method of teaching you to become aware of your body processes and help you learn to change them. Electrodes are placed on the skin and feed information into a small box attached to your computer via a serial port. The equipment feeds information back to you about your body. The feedback is usually auditory, a soft beep, and, by concentrating on this sound, the user can focus on specific bodily processes and learn to relax in very specific ways. The process is designed to provide the individual with an ongoing progress report as to how their body is responding to their own internal controls. In this way, one can learn to change heart rate, skin temperature, muscle tension, and certain brain wave patterns.

The difference between the two technologies is that light and sound machines provide direct stimulation that affects the rate of brain waves, whereas biofeedback places the impetus on the individual to control their body's processes themselves. The goal of biofeedback is to train oneself to respond to intrinsic cues, which contrasts to the light sound stimulation machine's purpose of matching one's brain frequencies to outside stimulation.