SOUND AND THE MIND
Human beings have used sound throughout history as a ritual tool to alter consciousness. Shamanic and religious traditions across the world use sound, rhythm, and repetition to bring about heightened states and attempt to open communication with the divine source, the spirit realm, the ascended ones, the ancestors, or the gods.
There are many different experiences and beliefs across different cultures, but the similarities in the use of sound to bring about these numinous states is striking.
The Brain, Frequency and Meditation
Your brain operates at differing frequency levels. Brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other, and the various bandwidths broadly correspond to different mental states. These are:
Beta 13-30 Hz: This is the wide-awake alert state when attention is directed towards cognitive tasks and the outside world. Beta mind is problem solving, judgment, decision making, or focused mental activity.
Alpha 8-13 Hz: This is the frequency most associated with creativity, imagination and flow. It is also the brain state associated with relaxation, tranquillity and daydreaming. Alpha is the resting state for the brain.
Theta 4-8 Hz: Theta borders on sleep and is a meditative state. In theta, our senses are withdrawn from the external world and focused on signals originating from within.
Delta 1-4 Hz: This is deep, dreamless sleep. Delta is the bandwidth of the unconscious mind. Healing and regeneration are stimulated in this state, and that is why deep restorative sleep is so essential to the healing process.
(Note: 1Hz is one cycle per second. The lowest frequency a human can hear is 20Hz)
The Hypnagogic State
The borderline between Theta and Delta corresponds to a level of awareness called the hypnagogic state. This is the transitional phase between sleep and wakefulness that we pass through where the mind is still conscious but the body has fallen asleep, and where the dream realm or subconscious rises into conscious awareness. This is usually a fleeting experience but one can sustain this state through the practice of meditation.
The hypnagogic state may be attended by a wide variety of sensory and mental experiences which can occur in any modality, individually or combined, and range from a deep sense of peace to vivid visions, lucid dreaming, intuitive problem solving, energetic shifts in the body, insights, and emotional and physical release.
Reaching this state allows the body to relax very deeply and has been shown to help with insomnia, depression and anxiety. Participants often report having deep, restful sleep after a session. Using sound as a meditation tool allows relatively quick transition into this state and holds the practitioner there.
How Sound Works On The Brain
Gongs and Tibetan bowls create a rich sonic field filled with low frequency pulses that interact with one another and have both a physical and psychological effect on the listener. The physical effects help to change frequency of the brain through a process called entrainment.
Brain Entrainment
Brain entrainment refers to the capacity of the brain to naturally synchronise its brainwave frequencies with the rhythm of periodic external stimuli, most commonly auditory, visual, or tactile.
When scientists first developed the technology to be able to record brainwaves they discovered when monitoring experienced meditators that their brain was operating at the Theta/Delta border for sustained periods.
In attempting to recreate this state using external stimuli (and avoid the need to spend all those pesky decades practising) it was found that the brainwaves will fall into alignment with pulses from external sources. This spawned the binaural beat technology used on a lot of meditation and self-help recordings, brain machines that flash light pulses onto the eyelids and various other audio, visual and sensory modalities.
Brain entrainment also offers an insight into why the use of trance drumming, repetitive chanting, gongs, bells, mantras and other sonic techniques may have evolved as they did in the spiritual traditions of the world.
Binaural Beats
Binaural beats are a way of creating low frequency pulses in the brain by playing slightly different frequencies in each ear. The pulse speed is the difference between the two tone frequencies. For example, to entrain the brain to the Theta state you could play a 100Hz tone in one ear and 104Hz tone in the other, which creates a perceived third 4Hz pulse in the centre of the head and the brainwaves will synchronise with this pulse.
Both gongs and Tibetan bowls create pulses in the Theta/Delta range and aid the practitioner in accessing the meditative mindspace.