Which Shure earphones are best for use with brain wave generation software, meditation CD's, or sleep learning systems? Does Shure make earphones that provide frequency response down to 5 Hertz?
A number of people have inquired about which Shure earphones are best suited specifically for use with "brain wave generation" software or "sleep learning" systems. There seems to be some confusion about the frequency response range required for the headphones or earphones used with these systems. Most of these systems induce a relaxed or drowsy state of consciousness that is associated with the presence of Theta waves in the brain, which have a frequency of from 4 to 8 Hertz. The brain can be caused to change to this mental state by exposing it to waves in this frequency range. Many people mistakenly believe that the headphones or earphones used must be capable of reproducing sound at these extremely low frequencies. This is not the case. The process utilizes a principle called "binaural beats", in which the two ears are independently presented with tones in the normal audible range that are 10 Hertz apart (500 Hertz and 510 Hertz, for example). The brain detects and responds to the difference between the two tones just as if it were "hearing" a 10 Hertz tone directly. In reality, conventional audio equipment (CD players, headphones, etc.) is incapable of reproducing frequencies this low, and the human ear is incapable of hearing them. If it were possible, then headphones would not be required for brain wave generation -- you could simply pop a CD into a stereo and play the 10 Hertz tone through speakers. But the binaural beats process requires that each ear is presented with just one tone in isolation, which dictates the use of headphones or earphones. Virtually any headphones or earbuds can reproduce these lower-midrange tones well. The choice of which earphones to use, then, comes down to comfort, fit, and isolation. Shure earphones fit into the ear, with interchangeable sleeves that provide a customized fit that is comfortable even after hours of wear. Because they are so small, they protrude from the ear very little or not at all, making them comfortable with the head on a pillow. And their design isolates you from background noise, allowing you to fully experience the subtle sounds of these types of recordings no matter where you are. The ideal Shure earphones for this application are the E3c or E4c models, because they are the smallest.