EDITORIAL : TV RATINGS BOMB INDUSTRY SHOULD HEED CALLS FOR MORE DETAILED GUIDELINES.

A consensus is growing to stop Jack Valenti, president of the Motion Picture Association of America, and television executives from implementing meaningless guidelines that would do little to help parents determine appropriate TV programs for their children.

Valenti's response to criticism that the proposed guide will not tell parents specifically whether a program contains sex, violence or foul language was inappropriate and childish and almost certainly guaranteed to backfire. Valenti said that if critics or the government try to force such a system, ``we'll be in court in a nanosecond.'' (A nanosecond is one billionth of a second.)

Valenti should read and heed the warning signs. When such liberal, industry-friendly bastions as the Los Angeles Times editorialize in favor of stronger guidelines and call for groups other than TV producers to set standards, something profound is going on.

Parents are demanding more than a one-rating-fits-all approach to television, such as the one that Valenti invented in the '60s for movies. Groups including the national PTA, American Academy of Pediatrics and Children's Defense Fund also have joined in asking TV to do better. And rightly so.

A new national study released last week shows why Valenti must not be allowed to bully his way through this issue. The analysis study found that, overall, 75 percent of family hour shows contains some sexual content, up from 65 percent in 1986 and 43 percent in 1976. That increase was not lost on parents.

More than 43 percent of the parents surveyed say they worry ``a great deal'' about how much sex their children see on TV.

This does not need to be a bloody political showdown. Free speech and open expression are fundamental values in this country, and no one is asking TV producers to give that up.

Instead, parents are simply asking for help. Guidelines similar to the existing motion picture ratings system for television, such as PG-14, TV-PG and TV-G, are inadequate.

It's far better to recognize the demand for more detailed information now than to force a confrontation before the Federal Communications Commission, which must approve the plan, or - worse - in the courts.

And is it really that hard? Obviously, not for cable. HBO already uses a content-based rating guide that labels shows for sex, violence and profanity, each on three levels of severity, and explains why.

If cable can do it now, why can't network television do it tomorrow as requested by the consumers who want and need it, instead of a decade from now when no one is watching their profanity-laced, smutty shows?

This is still a free country and this is a voluntary program. If Valenti is too stubborn to take a common-sense, workable approach, parents can always voluntarily turn off their sets and stop buying the products that pay for the shows. And they can do it faster than a nanosecond.