I read this in Blue Heaven by C. J. Box:
"He'd come to the conclusion that although it was possible for country people to move to a city and eventually adapt, it didn't work the other way around. He'd never fully get used to doing without; not having a vast choice of restaurants, grocery stores, shopping, the welcome blanket of anonymity within a white noise soundtrack."
What is "the welcome blanket of anonymity within a white noise soundtrack"?
"White noise" is technically a random electronic signal with flat power spectral density. It is that hissing sound you get on radios when you are searching for a station. It is also used to blank out irritating noises if you suffer from tinnitus.
The sentence is suggesting that urban man enjoys a sense of anonymity in the overall noisiness and bustle of the city, whereas in the country his actions will stand out.