Professor Anil Seth gives a TED talk on hallucinations. It is terrific and very helpful in seeing how our minds work. A friend of mine advises the use of the word "illusions" instead of "hallucinations". Use Google for "Anil Seth TED talk".
The question is What is consciousness? Or, how do we become conscious? I highly recommend his TED talk, maybe watching it more than once. He says that we hallucinate ourselves into existence. As he was speaking, I could imagine a nine month old baby crawling along. Seth makes a point that much of what we do and think involves predictions our brains make about the world. Way before nine months, I learned that when I see a ball and reach out for it, my hand will touch it and send me nerve impulses that mean the ball has been touched. I have read that the baby makes 2 million new synapses per second. So, you can see that by the time, we are five or six whole years old, we have seen and experienced a great deal. We have lots of experience on which to base predictions of what is in the world and how its contents act.
My hearing is limited although hearing aids help very much. Still, throughout the day, I have to say to Lynn and others, "I'm sorry. What did you say?" So, when Professor Seth played a squeaky short recording, I could not understand it, even when he played it a second time. Then, he spoke the words the squeaky sound bite contained in a normal clear voice. Then, he played the recording again and my ears could clearly hear what they had not detected successfully before. He re-played the recording and I couldn't help hearing what it actually said even though moments before, it was incomprehensible.
Internal awareness is different from external. We learn what a stomach ache and what hunger feel like. We learn what sleepiness feels like. Seth is of the opinion that much of what we do, experience and feel is very much related to the fact that we live as bodies and that we are built to stay alive and survive. Interestingly, I just recently learned of the book "Philosophy in the Flesh" by Lakoff and Johnson. Those authors try to re-examine and propose modifications in Western philosophy that explicitly face the fact that we humans are living animals in bodies. They want to change the traditional Western approach of disdain for the body and face head-on the fact that we breathe, eat, sleep and process all our thoughts in heads that are connected to the flesh.