“THE LATE SHOW STARRING JOAN RIVERS,” 11...

“THE LATE SHOW STARRING JOAN RIVERS,” 11 p.m. Thursday (11)--When Joan Rivers talks, people listen.

The question is how many will listen night after night after night? And will they prefer the hyper Rivers over increased late-night talk options and first-run action programming on CBS?

Centerpiece of the new Fox Broadcasting Co.’s fourth-

network plans, Rivers’ hour show has been the focus of speculation and controversy as she prepared to battle her alma mater, “The Tonight Show Starring Johnny Carson” on NBC, where she had been Carson’s permanent substitute host.

There’s been coverage galore of Rivers’ stormy breakup with Carson and her reported $10-million contract with Fox, covering three years.

The Carson show airs at 11:30 p.m., a half-hour after Rivers’ starting time on most of her 79 stations.

The feuding-talkers angle persisted and it was initially overlooked that this was less a late-night duel than a free-for-all. After all, King World’s half-hour “Nightlife” (on KCOP Channel 13)starring Carson-alumnus David Brenner is also being aired at 11 p.m. in many markets opposite Rivers.

Adding to the late-night talk blur are “The Dick Cavett Show” on Tuesdays and Wednesdays and “Jimmy Breslin’s People” on Thursdays and Fridays. Both are ABC entries initially envisioned as midnight talk shows following “Nightline.” But affiliate clearances are so tenuous and air times so fluid (KABC-TV Channel 7 is slotting Cavett at 2 a.m. and Breslin at 4 a.m.) that ABC hasn’t been listing airtimes in press releases on the two shows.

Is Carson too stale? Is Cavett too brainy? Is Pulitzer Prize-winning columnist Breslin too unknown? Is Brenner lost in the crowd? Is Rivers too abrasive?

Can she talk? More to the point, can she survive?