Narcissistic Self Absorption
A malignant narcissist is fixated 100% of the time on his image. To the exclusion of virtually all other sensation — sights, sounds, smells, tastes, and feelings. In other words, he is absorbed in/by his image. In that state, his brain filters out (tunes out) all other information. This is a habitual, more or less permanent state of consciousness. The result is that a narcissist misses an astonishing amount of what's right before his eyes.
For example, a narcissist often fails to notice even a drastic change in the weather outside. My most memorable observation of this occurred while I was getting hectically blabbed at by a narcissistic woman who thought I should be interested in every mundane thing she had to do that day. A few errands and a trip to the grocery store. Oh, she was so busy, busy, busy and these household chores were so demanding. Especially on this gloomy day in the rain. My jaw dropped, because we were standing next to a bank of huge windows, showing that the sky had cleared a couple hours ago and that the sun was brilliantly shining.
Narcissists get so self-absorbed that they filter out (as background "noise") an astounding amount of what they see, hear, touch, taste, and feel. The result is that they live in a kind of hypnotic, autistic state.
Since the narcissist identifies with his image, his absorption in it is self absorption. It's like absorption in a book or a computer or television screen. People with good power of concentration can become absorbed in thought. In fact, to some degree, we are always absorbed in whatever we are paying attention to. Our ability to become absorbed enables us to focus, or concentrate. Great tennis players, for example, report being so absorbed in the approaching ball, that it actually seems to grow larger, filling their field of view. The result is — whack — a beautifully heavy shot right off dead-center on the strings.
Our brains accomplish this focus by filtering out 99% of the information they receive and diverting it to areas in unconscious zones. There, it does not distract us. For example, that's what your brain is doing right now with the sensation of your butt pressing down on the chair you're sitting in. Right? You were unaware of that sensation, till I mentioned it. Then it instantly leapt to consciousness. That's because the brain is a relational database that immediately retrieved that information, calling it to consciousness when it was referenced.
So, a narcissist's absorption is just an extreme degree of the same thing. When you are talking with him, he isn't paying attention to what you're saying. He's absorbed in the image of him your behavior is reflecting.
The narcissists I have known well really seem to find it hard to pay attention to what you're saying, even if they want to.