Simon, who became a father for the first time in February when his girlfriend Lauren Silverman welcomed her second son on Valentine's Day, told the Daily Mirror that when Eric is sad, it doesn't last long.
"He's been a very, very happy baby," said Simon. "The other night I heard him cry at 4.30 in the morning so I went up to see him and within five minutes he was back to sleep, happy again."
Simon and Lauren are said to already be planning on having another child
The X Factor judge went on to say that Eric's arrival had brought colour and noise to his home in LA – although he was quick to say that if Eric is anything like his father, it won't last forever.
"I don't really like bright colours in a house," he said. "I think they're annoying.
"His room is the most colourful room in the house, until he reaches seven. Then he'll be like me."
Little Eric will turn one in February
The 54-year-old said his son had brought a "new energy" to his home, adding: "It definitely feels more like a home. There's more of a nice atmosphere.
"It's definitely louder but not to the point where everybody thought I was going to be getting up at five in the morning and all that kind of stuff."