It's not something I've measured, but rather a feeling. Specifically, the blockage in the back of my right eye seems to have cleared, and I feel like the right side has slightly expanded outwards.

Recently, there have been cracking and creaking sounds in the center of my head and the upper half of my head, and while it's just sounds and cracking, sometimes there's a clear sensation, although it's a small feeling. Along with that specific feeling, I feel like my head is gradually loosening, expanding outwards, and becoming more relaxed. Although it's a very small sensation, it's a relatively large difference in terms of the feeling in my head. It's as if tension that I hadn't consciously noticed before is being released, leading to deeper relaxation, and allowing my mind to move more freely. I feel like it's making it slightly easier to achieve Samadhi (a state of meditative absorption), and that the state of oneness is becoming (slightly) easier to maintain.

It's deeply affecting not only the body but also the mind.

Although the center and upper half of my head are not completely relaxed yet, I feel like the relaxation is gradually progressing. I'm noticing this steady change every day, even though it's a small step at a time.

Usually, when I start meditating, there are cracking and popping sounds almost immediately, but sometimes, after about an hour or two, subtle but steady changes occur.

Also, there are times when changes occur while I'm falling asleep, and it feels like my head is loosening and steady changes are happening.

I think the changes that occur while sleeping are probably due to the fact that I'm meditating. I don't think there would be much change if I were just sleeping. The changes that I consciously notice mainly occur during seated meditation, but even when sleeping, there's a possibility of change, although it's only a little. In any case, both have the potential for change.