Especially during meditation, or even in my normally calm daily life, I feel a crackling, sometimes a popping sound, repeatedly in the back of my head, as if it's loosening.

The area in the back of my head, slightly below the center of my head, feels particularly loose. This loosening started about half a year ago, and I've occasionally experienced similar sounds in the past, but recently, for the past day or so, it's suddenly started making loud noises in that area.

I wasn't consciously focusing on that area, but recently, I've been focusing on the left and right sides of my head. By focusing on the right side, from the center of my head towards the pingala, I try to distribute energy throughout the right side of my body. Similarly, by focusing on the left side, from the center of my head towards the ida, I try to distribute energy throughout the left side of my body, during meditation and in my calm daily life.

As a result, I feel a gradual distribution of energy on both sides of my head. However, recently, suddenly, the back of my head has started making relatively loud crackling and popping sounds. I wasn't particularly focusing on the back of my head, but it suddenly started making (relatively loud) noises.

It's as if, while focusing my awareness within my head, the location where the sound is coming from suddenly changed.

About a month ago, the back of my head felt like it was moving as if inflating a balloon. Up until that point, it was just the beginning of movement, but now, it seems like it's truly starting to loosen.

Some schools of thought say that the back of the head is a key area. Some say that during meditation, energy flows from the ajna (third eye) in the forehead, passes through the back of the head, and then connects to the sahasrara (crown chakra) at the top of the head.

On the other hand, some people talk about the aura as if the entire head is connected. Perhaps, once it's connected, it's simply a matter of connecting the top and bottom, but I hypothesize that there's a stage where it initially passes through the back of the head. However, this is just a hypothesis, and I need to verify it.

Although it varies depending on the school of thought, it's often said that the center or the back of the head is the final point. I recognize it as the back of the head, but it could also be considered the center of the head, as the pineal gland is slightly behind the true center of the head. Whether it's recognized as the center of the head or the back of the head (although it's slightly inside) may vary from person to person. (This is a hypothesis.)

Furthermore, or literally, perhaps the occipital region is being activated separately from the pineal gland.

In this area, various things are said in terms of both sensation and literature, and there is no consensus, so it is a subtle matter. However, I will continue meditating without worrying too much about it.

I still have challenges with the connection between the left and right sides of the head, so I am not focusing only on the occipital region. The basic approach is to be aware of both the left and right sides of the head (Ida and Pingala) while meditating. The focus of consciousness moves from each side to the center, near the eyebrows, and then to the opposite side. However, when the consciousness passes through the area near the eyebrows, the occipital region naturally crackles and relaxes at that moment (when the consciousness is near the eyebrows, which is a relatively transitional state).

Since there are still challenges in various parts of the head, I am focusing on meditating to activate the entire head, especially emphasizing the connection between the left and right sides.