Mind machines typically consist of a control unit, a pair of headphones and/or strobe light goggles. The unit controls the sessions and drives the LEDs in the goggles. Professionally, they are usually referred to as Auditory Visual Stimulation Devices (AVS devices). The light and sound machines relaxation technique truly must be experienced to understand.

Sessions will typically aim at directing the average brainwave frequency from a high level to a lower level by ramping down in several sequences. Target frequencies in higher-end machines are typically in the alpha wave area in the frequency range of 8-12 Hz, or in the beta wave area in the frequency range of 13-40 hertz (Hz), and can be adjusted by the user based on the desired resulting effects.

Mind machines are often used together with biofeedback or neurofeedback equipment in order to adjust the frequency on the fly.

Safety

Rapidly flashing lights may be dangerous for people with photosensitive epilepsy or other nervous disorders. It is thought that one out of 10,000 adults will experience a seizure while viewing such a device; about twice as many children will have a similar ill effect.