The Voice of America has sharply increased its Polish-language broadcasts to Poland since the martial law crackdown four weeks ago, and the Soviet Union has sought to counter them with large-scale jamming, the International Communication Agency said yesterday.

The United States protested the Soviet move in the war of the airwaves by calling Soviet Ambassador Anatoliy F. Dobrynin to the State Department late Thursday and demanding that the radio interference cease immediately.

State Department spokesman Dean Fischer, who announced the protest, said Undersecretary of State Walter J. Stoessel Jr. told Dobrynin that the jamming is "totally unacceptable" and violates several international laws and conventions.

The Voice of America broadcast in Polish 2 1/2 hours per day to Poland before the declaration of martial law Dec. 13. This was stepped up to 3 1/2 hours daily on Dec. 16 and more than five hours daily on Dec. 18.

According to ICA spokesman Henry Ryan, much of the additional programming was devoted to worldwide reaction to the Polish events.

Starting Dec. 28, the VOA broadcasts were subjected to heavy jamming that U.S. monitors traced to four sites in the Soviet Union, including Moscow, Kharkov and Gorky.

No jamming of the broadcasts from within Poland was detected, according to officials.

The VOA responded Dec. 31 by increasing its daily Polish-language broadcasting to seven hours. Use of a variety of transmitters and channels has made the broadcasts more difficult to jam.

U.S. officials said that, despite heavy interference, there is evidence that VOA is getting through to a substantial Polish audience.

Soviet-based jammers also are reported to be interfering with Polish-language broadcasts of Radio Free Europe and the British Broadcasting Corp.

But the State Department said the Polish programs of the West German official radio, Deutsche Welle, and those of Vatican Radio are not being jammed.

The two hours daily of medium-wave broadcasts to Poland of the Voice of America have not been jammed, apparently because it would be extremely difficult to do from the Soviet Union, officials said.

Voice of America broadcasts to the Soviet Union in Russian and seven other local languages have been jammed consistently since the beginning of large-scale labor and political controversy in Poland in August, 1980.

ICA spokesman Ryan said the United States protested shortly after the interference began, but that the Soviet Foreign Ministry denied official complicity, saying the problem resulted from "bad transmission."

The State Department, in announcing the protest to Dobrynin, said it categorically rejected charges from Soviet media that VOA broadcasts are "subversive activity" directed at Poland and the eastern bloc.

"VOA carries objective news and information denied the Polish and Soviet people by their own government-controlled media," the State Department said.