In Naad-Yoga practises it's recommended to close your ears with cotton or earplugs or with the fingers of your hands. It facilitates listening subtle cosmic vibrations. When vibrations are quite high in the body of a Yogi--he can feel them. It can be clearly understood that when you attentively keep listening subtle cosmic vibrations--your frequency of vibration also rises because of the brain-waves entrainment. The frequency of the cosmic vibrations is very high compared to your usual vibrancy and as they entrain your body it also starts vibrating at a higher rate. Now there might be a confusion about low and high frequencies but those who have read about brain-wave entrainment using binaural beats know that ultra high frequencies and ultra low frequencies do the same type of entrainment--they're kind of intermodulated. Which means that the ultra high frequencies carry the ultra low frequencies and ultra low frequencies carry ultra-high frequencies hidden inside them. The resultant effect produced by them is similar.
There's an observation which intrigued me. When paying attention to vibrations it's quite obvious why your frequency of vibration should rise. It's because entrainment is happening. But what about the case when you don't pay attention to the vibrations? The frequency of vibrations should not keep rising--it should fall down very soon as you don't pay attention. Isn't it logical?
But it doesn't work that way in real-time. If your frequency is high enough you would observe that if you keep your ears closed and don't pay any attention to vibrations--then too frequency of your body would keep increasing--which means your vibrancy would keep increasing.
What might be the cause of this? I asked myself.
At first it seemed that it's because ears somehow drop the vibrations out. I really visualized vibrations falling out of my ears. But later on, I realized that it seems kind of awkward--so then I intuited that actually when you open your ears--external sounds start entering inside your body and start mixing with internal vibrations--they entrain down the internal vibrations and hence frequency of vibrations decreases. But if you don't open your ears there's a certain momentum inside which remains inside and conservation of energy helps increase this momentum further.
So at higher frequencies--it doesn't matter if a Yogi is very attentive of vibrations--just closing his ears would elevate frequencies a great deal. There might be an objection in someone's mind about the increase in the frequency of vibration--because it's apparent that reverse entrainment doesn't happen when ears are closed but what about the loss of energy because of the inattention--the energy which is lost in thoughts? This might be answered clearly only when a practical is done--but in theory--at high frequencies--the rate of loss of energy is much lesser because thoughts don't have a great grip--or alternatively you might propose that some part of you is still listening to the word even when you're not attentive.
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