Thank you for your reply.
What if there is no feeler or noticer at all? What if a subject (feeler or noticer) is just assumed without any roots in reality?
I've been looking/inquiring since the date of your reply. I'd say at first there were still some expectations from this looking, such as "experiencing nothing" or "experiencing silence" and a believe that "I am not these thoughts, I am the one noticing".
What can be said about this "nothing" is that there is nothing fixed or stable that can be said to be an "I" or "Karla" or "me". etc. What can be observed are are thoughts, bodily sensations, and the experience of the sounds, visions, touch, etc. that are always changing. Even the thoughts about "I" or "Karla" is always changing So, there are only thinking, noticing, feeling and sensing themselves. No one thought or feeling is good/bad, expect for a thought commenting whether the previous thought/feeling is good or bad. Bodily sensations can be felt regardless the commentary/thought/label that they are "painful" or "pleasant", etc, these sensations were already felt before the label and doesn't matter what the thought "say". The thoughts can't do anything to get rid of them or produce more of these senations.
And what is ignoring thoughts? Is there anything doing it? Or ignoring is happening on its own?
The idea of "let's ignore thoughts for a moment" or "let's not refer the thoughts" are just thoughts. After such thoughts, sometimes there are shifts in attention or focus. It was assumed that there was a doer that shifts the attention or focus. However, after a while it can be noticed that attention/focus just wanders by itself.
Sensations are here. They are happening. But are there sensations of Karla? Or a sensation of me? Or a sensations of a person? Or a self?
No, there are no sensations of Karla. When there is pain (recently got a stomachache), the pain can be felt, but there is no sensation of the feeler of the pain, only thoughts or commentary of the pain, sometimes there are just label like "painful" and sometimes with an "I" like "I need to drink more water", but this "I" that "need to drink more water" can't be felt. It is just a thought that passes. In fact, while doing other activities, the stomachache are often just noticed or recognized as just pain.