A Light and Sound Device (LSD), also called a Mind Machine or Audio Visual Stimulation device, uses flickering lights and special sound frequencies to stimulate the mind in different ways. There are many programs that can be used to relax, meditate, sleep, learn, energize, visualize, for entertainment or to induce deeper hypnotic states.

The device consists of a light/sound synthesizer, stereo headphones and eyeglasses with small lights mounted on the inside. Brain waves are the electrical activity of the brain that can be measured by an EEG (electroencephalogram). They are a mix of many frequencies that range from less than one Hertz (cycles per second) to more than 40Hz. Neurologists have found that there are several levels of brain activity. See below:

The LSD emits predetermined (depending on the program chosen) sound frequencies, pitches and tones synchronized with the lights which cause the brain waves to pulse at the same frequency. Left and right brain hemisphere become synchronized and your mind is able to reach deep inner states associated with the different brain wave levels.

How is it used?

Close your eyes, put on the glasses and headphones and enjoy. You’ll hear drum like intricate sounds and the flickering lights might create moving, colored dynamic shapes and patterns that can turn into visions or whatever your imagination wants you to experience. Different people have different experiences, usually depending on how well you are able to let go completely without expectations. The LSD can be used alone or in conjunction with hypnosis and guided imagery.

What are the benefits?

The light and sound stimulation has a powerful effect on mood and emotions. It can be used for many things such as to reduce stress, enhance creativity, induce sleep, achieve calm and relaxed states, or energize your body and mind. It can also be used as a tool to reach deeper levels of trance when used in conjunction with hypnosis and guided imagery. It will make it easier for the subconscious to receive beneficial suggestions and to create desired imageries.

History of Light and Sound Devices

People have used flickering lights to stimulate the mind for centuries. Around 200 A.D. Ptolemy noted that flickering lights could cause lightheadedness and euphoria. Ancient shamans and tribes used lights and drumming sounds to alter the state of mind.

In 1940’s and 1950’s a neuroscientist W. Gray Walter noted that the brain wave pattern of the entire cortex was changed after flickering light stimulation. In the 1960’s and 70’s more experimentation was done which showed that adding pulsing sound enhanced the experience.

Medical Disclaimer

The LSD should not be used by anybody with any form of seizures, epilepsy, visual photosensitivity, cardiac arrhythmia, other heart disorders, or by those using a pacemaker. Nor should people who take stimulants, tranquilizers or psychotropic medications, including illicit drugs and alcohol, use it.

There is a small risk that you could be photosensitive and not know about it and exposure from flickering lights could cause a seizure. Most persons with photosensitive epilepsy have a first seizure during their teenage years, 75% by age 20. 25% of the persons who are sensitive during their teenage years outgrow the condition by age 25. The likelihood of being photosensitive and not knowing about it is 1 in 4000 for children and 1 in 20,000 for adults over 25. So the risk is very small. Even if you are diagnosed with epilepsy, there is only about a 5% risk that you are photosensitive.

Ask for your doctor’s advice and supervision before using any kind of light and sound device if you ever have suffered from any kind of head injury or concussion, are sensitive to bright or pulsed light, or find that such light can cause headaches or other discomfort.

If you experience any kind of discomfort, uneasiness or nausea, when using the LSD immediately remove the glasses and end session.