Aaron Sorkin’s “The Newsroom,” the big new series of the summer that premieres Sunday night on HBO, fails to meet the high expectations that greet it, save one: It is crammed with incessant gibber-jabber.

Characters never stop speechifying to one another, replacing believable dialogue with that unmistakably Sorkinesque logorrhea of righteous self-importance. It’s a puppet show with Sorkin as the only hand, expressing his displeasure with the tenor of public discourse. (Which everyone knows has reached an unctuous low.) “The Newsroom” is principally concerned with how American society has been ruined by the blaring insipidity of our 24-7 media culture. The theme song swells with a collage of images of the founding fathers of television news, but if Edward R. Murrow is watching, I suspect he’s chuckling in his grave rather than spinning in it. (Fun fact: Murrow was cremated.)

Jeff Daniels stars as Will McAvoy, a straight-down-the-middle prime time anchor on a straight-down-the-middle cable news network. While sitting as a guest on one of those state-of-journalism panel discussions at Northwestern University one evening, McAvoy snaps (an homage to “Network’s” Howard Beale) when a wide-eyed student asks him what makes America great.

His answer is long, contrarian and witheringly mean to the young woman — a cathartic release for the “kids today” crowd. Rather than meet his remarks with applause, the twittersphere collectively blows Will a raspberry. In a moment of managerial crisis control, he goes on a brief sabbatical.

When he returns, his 8 p.m. show, “News Night,” undergoes a complete makeover. An idealistic new producer (Emily Mortimer as seasoned war correspondent MacKenzie McHale) is brought in to rally the bright young things on the staff and redefine Will (her former lover) as an Olbermann-esque truth teller — another “Network” homage, with unenthusiastic dollops of “Broadcast News” on top. During a board meeting, MacKenzie pronounces three requisites for every “News Night” segment: Is the story relevant in the voting booth? Is this the best possible form of the argument? (which means no blowhard guests) And is the story part of a historical context?

Off they go, merging onto what they regard as the journalistic high road. A twist for Sorkin (but not for viewers), is that Will is a Republican who has taken it upon himself to challenge the party’s rightward fringe, providing a novel new way to present a Democratic fantasia. “I’m a registered Republican,” Will says in a prime example of elegant Sorkinese. “I only seem liberal because I believe hurricanes are caused by high barometric pressure and not by gay marriage.” Real events from 2010 and 2011 — including the BP oil spill, the midterm election that ushered tea partiers into Congress and the Gabrielle Giffords shooting in Tucson — form the backdrop of Will’s newly located outrage. His pulpit gets a nightly workout on air and a constant workout everywhere else.

The word pile that once seemed so melodious in Sorkin’s other projects — especially that millennial anti-anxiety medication known as the “The West Wing” — now has the effect of tinnitus. The men talk like Sorkin writes; the women talk that way, too; the 28-year-olds talk like that, as do the 41-year-olds, as do the cast’s septuagenarians, who include Sam Waterston as the head of the network news division and, later on, Jane Fonda as the network owner who puts the arch in matriarch. (In other words, Jane Fonda as Ted Turner.)

At one point in the first episode, MacKenzie delivers not one, not two but three grandiloquent monologues to Will, one right after the other. Sorkin’s writing lapses into self-parody, leaving savvier viewers to marvel at how quickly the show goes awry. And anyhow, HBO already has a compelling series in which whip-smart people of various political persuasions gather to out-argue one another and bemoan the state of media ignorance. It’s called “Real Time With Bill Maher.”

There are a number of possibly irreparable miscalculations going on here. The first is that, no matter what “The Newsroom’s” producers and writers might think, journalism just isn’t very much like politics. The brain-wiring between reporters and politicos is more different than most people realize, and the high-profile personality who traverses between them (George Stephanopoulos, say) is more of an exception. Yet, from Sorkin’s keyboard, these are all the same kind of folk, thriving merely on their own highfalutin’-ness, determined to shape forces beyond their control, and determined to do it with talk.

This makes “The Newsroom” an exponentially tedious undertaking for the viewer, when really all the show needs to be is slightly sardonic, occasionally frantic and mildly amusing. By episode four, you can feel some tardy recognition of the overwriting, some adjusting of the show’s knobs. The haranguing soliloquies are reduced by 30 percent and become slightly more like the romantic banter we crave; some villains are established; some wan love connections are presented for our consideration. By then, however, you already dislike the characters too much to care.

The behind-the-scenes drama of making television is a favorite Sorkin milieu, going back to his enjoyable and too-brief “Sports Night” from 1998 and his less-enjoyable (and faintly praised) “Studio 60 on the Sunset Strip” from 2006.

Sorkin won an Oscar in 2011 for penning the “The Social Network” screenplay, but that is precisely when his writing began to strike me as atonal and even farcical — when a bunch of supersmart millennials creating Facebook had Sorkin-style repartee crammed into their mouths, making them all sound twice as old as they were. “The Social Network” was an older generation’s idea of what the younger generation should sound and act like.

Daniels and company are likewise saddled with words that people can write but hardly ever say. This is not always bad. While on a disastrous dinner date, the caddish Will challenges his companion’s love for “The Real Housewives of New Jersey.” Who would watch that junk with a clear conscience?

“It’s called a guilty pleasure,” she tells him.

“The chocolate souffle on this menu is a guilty pleasure,” Will contends. “The Archies singing ‘Sugar, Sugar’ is a guilty pleasure. Human cockfighting makes us mean and desensitizes us. . . .

And off he goes, telling us what Sorkin wants to tell us about our cultural addiction to reality TV. This preachiness is itself a kind of guilty pleasure, but with not nearly as much pleasure as it once had.

The Newsroom

(one hour) premieres Sunday at 10 p.m. on HBO.