The “noise” is randomly scattered throughout the book, and it distracts our attention from the book’s explanation. So the noise is creating the following problem: Every time you read a book, you miss important information. All non-fiction books come with the “noise” problem built-in.
The noise can be a sentence, a paragraph, multiple paragraphs, even a complete page. A typical book can have more than 100 cases of “noise” scattered in random places. That’s a lot of distraction.
Which explains why we tend to miss key messages and information when we read a full-length book.