People switch on their televisions for a variety of reasons — to keep informed on daily events, to learn something new, and of course to be entertained.

Most don't tune in just to get their eardrums blasted by a manic ad pitchman.

Complaining about volume levels in commercials is nothing new, as viewers have long had to endure product pitches that seem much louder than the programs they surround.

What's new is that some powerful groups are trying to do something about it.

The Commercial Advertisement Loudness Mitigation Act, or CALM Act, is now working its way through Congress after being proposed by Rep. Anna Eshoo (D-Calif.) in the House and introduced in the Senate by Sen. Roger Wicker (R-Miss.).

The act would require the Federal Communications Commission to prohibit commercials from being louder than the programs they accompany, and has been approved by the House Energy and Commerce Committee.

So far the act hasn't come up for full debate in either chamber.

Earlier this month, the Advanced Television Systems Committee, the entity that sets U.S. television standards, formally approved technical guidelines for networks and stations to eliminate wide variations in volume between programs and commercials.

Mark Richer, president of ATSC, told the Tulsa World that the entity has long heard the complaints, though coming up with a solution has taken time.

"We've actually been working on it for a number of years and precedes any activity being done on Capitol Hill."

Though the standards are voluntary and have no mechanism for enforcement, Richer said they do address the issues brought up by the CALM Act. ATSC has not taken an official position on the act.

Richer said stations already are putting the new standards into effect.

"Even before we finished the recommended practices, we've seen broadcasters start to implement the process," he said. "We've already seen quite a big improvement."

However, the problem can be more complex than it seems, said Gerald Weaver, director of engineering at KJRH. Often, his station has limited control over the volume of what they broadcast.

"We endeavor to control the volume levels as much as we can," he said. "In fact, we go to great lengths to do that. But unfortunately, there are certain things we have no control over."

Weaver said the problem often stems from the source of the material, not the broadcaster. KJRH will receive many programs recorded at lower volumes, and then have to pair them with commercials recorded louder.

Sound quality can also contribute to the problem, since more compressed sounds often seem louder than higher-quality sound, even when both are at the same volume.

Even now, HDTV programming with digital sound can be paired with standard-definition commercials with lower-quality stereo sound.

"Going from 5.1 audio to a stereo commercial does make it louder," Weaver said. "DTV has stepped it up to a level to where it's more of an annoyance."

Richer said his organization has tried to set standards that don't stifle creativity for show producers and commercial producers alike.

"The audio levels are set on a number of things, such as artistic choice and what makes a program or commercial effective," he said. "So there's a balance between not losing that and providing uniform levels so the audience doesn't jump out of their seat when commercials come on."

Though Weaver said commercial volume levels can be a problem, he's more supportive of industry-set standards such as ATSC's rather than federal regulation.