The grinding, predawn sound of trash trucks, highly popular among barking dogs, was criticized by the Environmental Protection Agency yesterday in a series of proposals aimed at reducing the impact of noise on Americans.

The EPA, calling for quieter trash trucks, recommended that a noise limit of 78 decibles - measured at 23 feet from the truck - go into effect in January, 1979. The present limit is 83.

Whether or not EPA agents will stake out trash trucks around the country to apprehend violators could not be determined yesterday. But even if they do, some spokesmen for the garbage pick-up business say, they could very well miss the main source of this early morning discomfort,

"Most of the complaints we receive are about the men themselves," said a spokesman for the D.C. garbage and trash service. "The sound of those metal cans hitting the streets seem to irritate people more than anything else."

The District, which has about 83 compactor-equipped trash trucks, begins collections at about 7 a.m. "Most people are usually up by then," the spokesman siaid.

For safety reasons, the trucks were recently equipped with bells and horns that ring and buzz when the vehicle is going backward. That noise has generated some complaints, the spokesman said.

As a remedy, some residents have been advised to buy plastic trash cans and garbage men have been asked to be more discriminating when driving in reverse or unloading the can.

In Prince George's and Fairfax counties, disposal service spokesmen said they were not aware of EPA's authority to mandate noise controls on existing trash vehicles.

"Improving the manufacturing of new trash trucks would be of benefit in those neighborhoods where the mornings are generally quiet," said Donald Bowman, Fairfax County's environmental affairs director.

"We have had some complaints about the compactors on trucks," said a spokesman for the Prince George's County sanitation department, "but most complaints stem from banging the trash cans against the concrete."

According to EPA Administrator Douglas M. Costle, further noise regulations will be proposed for buses, motorcyles, pavement breakers, rock drills and lawn mowers.

Costle said trash collection firms could expect to save about 995 per year per vehicle in fuel costs because the engine could operate at a lower speed.

The spokesman for the District trash service said he does not know how the trash compactors could be made quieter, "but we guess they have a way to do it."