For example; if one ear is listening to a tone set at 200 Hz and the other ear receives a tone of 209 Hz, the difference, in this case 9 Hz, is used to determine the effect. In this example, the difference of 9 Hz would be in the Alpha range.
Alpha brainwaves are the waves that are normal within the human mind when it is stress free. Alpha waves occur between 9 - 14 Hz. Children usually have higher normal Alpha waves than adults. Through the use of biaurals in the Alpha range, the listener can expect to promote a reduction in stress, a relaxed but alert state of mind and the able to absorb learning material more readily.
Some interesting Alpha waves frequencies are:
9 Hz Feeling of floating
10 Hz Associated with the sacral chakra
10. 6 Hz A relaxed but alert state of mind
12 Hz Learning frequency