Very interesting topic, King_Erlian!

Here are my thoughts. So many times we can deceive ourselves into believing a lie rather than believing the truth, on the grounds that the lie is easier to accept. Whether it is easier due to a currently held belief system, or due to the consequences of accepting the truth, etc..... it doesn't really matter.

If he saw a lion creating the world (which I do believe that he did see, and did understand) and obviously came to the conclusion that the lion was an animal, perhaps he thought that all other animals would be equally powerful as Aslan was, and therefore would be dangerous. For that reason, he decided to distance himself from them as much as possible, so that he could make his profit (by planting "bits of scrap iron," and growing them into railway engines, battleships, etc....) and be done with this world.

He was a very practical man. . . he wanted only to use this new world for what he wanted, and then to be done with it. The animals could have gotten in his way (in what manner, I can only speculate).

So he convinced himself that the lion wasn't actually singing, that what he was seeing must be able to be explained by another, more "logical" situation. The lion wasn't singing. . . it was just roaring to a tune. The animals weren't really talking. . . they were just cawing, cooing, crowing, braying, neighing, barking, lowing, bleating and trumpeting.

And after a while, he began to believe this lie, and as all of us know, once somebody believes a lie, it is very difficult to get them to believe the truth, which explains why he became unable to hear their voices.

"Aslan, could you say something to. . . to unfrighten him," Polly said, "And then perhaps say something that will make him never want to come back here again."

"Do you think he wants to?" Aslan asked.

"Well," replied Polly, "He's so excited about the bar of the lamppost growing into a lamppost tree, and he thinks. . . "

"He thinks great folly, child," Aslan interrupted. "This world is bursting with life for these few days, because the song with which I called it into life still hangs in the air and rumbles in the ground. It shall not be so for long, but I cannot tell that to this old sinner, and I cannot comfort him either. He has made himself unable to hear my voice. Oh Adam's sons, how cleverly you defend yourselves against all that might do you good."

As far as the other animals not being able to understand Uncle Andrew goes, this is not true. They could understand him. Uncle Andrew kept asking for brandy so much, that they figured that that must be his name, and therefore that's what they named him. If they could understand that snippet of speech, I'm sure that they could understand the rest of his speech as well. I merely think that your reference to sizzling noises came from Uncle Andrew's utter terror, and an inability to speak coherently. He was so frightened about being kidnapped by what he had convinced himself to be wild animals, that he was speechless, save for the mutterings of an old man, which would be completely incoherent to people who'd lived with Uncle Andrew for some time, let alone to a group of newly created beasts who'd just me this bizarre form of lettuce

I'm not sure what happened.

For those of you who have read the Space Trilogy, do you remember how at the climax of That Hideous Strength,

It seems as if the same thing happened here. I would guess that Uncle Andrew still thought he was speaking coherently.

As to his attitude to the animals, and how he could exploit them, that was the story of Uncle A's life. Look at how he used Digory and Polly, or his immediate thought upon seeing the way things grew in the new world. Even his relationship with his sister Letty was one of exploitation, having taken her money earlier, and then sponging off of her without any appreciation of the hardship he had caused.