Types of Brainwaves
Brainwaves are produced by our brains in whatever state of consciousness we are in: waking, sleeping, daydreaming, solving mathematical equations, dancing, singing, etc.. These brainwaves are measurable as electrical signals using a device called EEG (electroencephalogram).
There are four types of brainwaves and they differ in frequency ranges. The table below illustrates the brainwave types, the frequency range and a brief description.
|BETA||13hz-38hz||This occurs when we are fully awake. 2-20microvolts|
|ALPHA||8hz-13hz||Occurs when you are relaxed and not doing any major mental work. 20-60microvolts|
|THETA||4hz-8hz||Light sleep 20-100microvolts|
|DELTA||0.5hz-4hz||Deep sleep. 20-200microvolts|
The frequency range tells us how many times a brainwave pulses in 1 second expressed in hertz (hz). The fully awake state(beta) has the highest frequency range and gets slower as it goes to the sleep state (delta). As the frequency goes lower the amplitude or strength of the pulses goes higher.
The voltage levels (amplitude) are so small that they are measured in microvolts (millionths of a volt).
The waveforms presented above are uniform in shape for simplicity and does not represent the actual pattern as seen from an electroencephalograph as shown below.
When we are in the waking state or fully awake, we are in beta but it does not mean that there are no activities from the the other wave types. It's just the beta brainwaves are dominant and the rest have small signals or little activity. Likewise if you are in the alpha state, the dominant brainwave pattern is the alpha type while the rest are somewhat in the background but still performing the necessary functions for our body.
Using isochronic tones, we can selectively make certain brainwaves dominant. Some frequencies enhance our focus and concentration while some silence our conscious murmurs, and bring us to a meditative state.
Only a few minutes of listening to an isochronic tone can bring us to a desired state. A meditative state can be achieved much faster, memory can be improved, sleep much better, etc.