How can Screams mean Smooth?

"There aren't enough OOOOOOs in the word Smooth to describe this trailer" he claims. 

Has he himself ever taken a ride in one of his trucks I wonder? Would it be fit for his pets and family? 

"Much better than standard trailers" he brags as you hear a pig scream. I call out "It isn't much better- Is it!" It was almost as if the pig shook his head "No!"