The phrase "become closed off" is correct and is used in both spoken and written English.
You can use this phrase when you want to describe someone who is withdrawing from conversation, has become unresponsive or has become emotionally removed from a situation. For example, "After her mother passed away, Linda became closed off and no longer talked to her friends."
Some will complain that the soul of the market has gone, others that it has become closed off to locals.
When you feel like a fraud, your actions become closed off, sabotaging any chance you might have of growing your business and bringing in revenue.
Gradually, studios are learning that the popular genres – football sims, fighting titles, sandbox adventures – have become closed off to newcomers looking to go big.
Both types of the disease result from excessive proliferation of the epithelial cells lining the ducts and tubules of the kidney, so that the lumens of the ducts become closed off as cysts, which then expand, leading to a massive enlargement of the kidneys, which can become as big as an American football (figure 2d).
As the rest of Iraq became closed off to foreigners, I savored these sessions amid the chaos of waiters and dishes.
That the fundamental act of complaining becomes closed off to you when the bulk of the world has such a harder time in comparison.
Sometimes people become more closed off as they get older.
And if you don't answer the questions, you become bitter, closed off and cynical".
The scandal has drawn more attention to what critics of secret code have been saying for years: that the systems running our cars, homes and gadgets have become extremely closed off to us.
The situation is at crisis point, and institutions and the government need to act to introduce rent controls – otherwise we face a situation in which higher education becomes increasingly closed off to anyone other than the rich.
