That is right. Chomsky proposes 5 filters through which this process happens. These filters operate, according to Chomsky, not just in media, but in all of society. From kindergarten to our deadbeds.
I think this was best illustrated with Chomsky's 1996 interview in "The Big Idea" on BBC by Andrew Marr. Chomsky is outlining how the filters make sure certain viewpoints are popularized, and Andrew Marr asks "How can you know that I'm self-censoring?". To which Chomsky replies "I'm not saying you're self-censoring. I'm sure you believe everything you're saying. But what I'm saying is, if you believed something different, you wouldn't be sitting where you're sitting."
The 30 minute episode is well worth a watch, but the three minute clip of the above exchange is also available.