The Soviet Union today resumed selective jamming of Western radio broadcasts in Russian for the first time in seven years in an apparent effort to lessen the impact of reports of industrial unrest in Poland.

The jamming began this morning when the Russian-language broadcasts of West German's Deutsche Welle and the Voice of America were drowned by high-power Soviet transmitters on the frequencies used by the two stations. Later in the day, the Russian-language news program of the British Broadcasting Corp. was also jammed.

However, the VOA news program in Russian came over loud and clear at 9 p.m. Moscow time and included an item about the resumption of jamming.

In Washington, the State Department declared, "We deplore the fact that the Soviet Union has resumed jamming Voice of America broadcasts to the Soviet Union, as well as other Western radio broadcasts, for the first time since 1973. This act . . . is in clear violation of the provision of the Helsinki final act concerning the dissemination of information.

[" . . . One can only assume that Soviet authorities recently became concerned over the wide gap between the heavily censored news as reported to the Soviet people by Soviet news media and the news as carried by Voa."]

Soviet citizens who regularly listen to Western broadcasts said the resumption of jamming today might foreshadow a tightening of discipline inside the Soviet Union.

Diplomatic observes here believe that the Kremlin may be primarily concerned about preventing the publicizing here of demands by Polish Strikers, which include freedom of speech and press, release of political prisoners, the right to form free trade unions and access to mass media for all churches.

Such demands are clearly unacceptable to Moscow since they represent the challenge to the "basis of socialism" in Poland.MOSCOW, From A1>

The Western radios claim vast audiences here. BBC estimates its audience in the Soviet Union exceeds 10 million, and VOA is believed to have an even larger listening audience because it is on the air longer.

The Soviet Union and its allies jammed the VOA from the advent of the cold war in 1948 until 1963 when Nikita Khrushchey lifted a number of restrictions on information. The jamming resumed when the Soviets invaded Czechoslovakia in 1968 and continued for five years. It was halted just before the second preparatory conference on European security and cooperation opened in Genva in September of 1973.

The resumption of jamming today, however, was not regarded as a prelude to any Soviet involvement in the Polish unrest. Diplomats say that the Soviets remain reluctant to interfere directly in Poland but that they expect Polish authorities to contain the unrest before it could spread to other East European countries.

While the 1975 Helsinki accords do not contain any specific pledges against jamming, they mention an expansion of radio broadcasts as dessirable. Moscow's implicit pledge not to jam Western broadcasts was believed to have been one of the most agonizing concessions on the road to Helsinki.

Soviet officials acknoledge that too many educated listerners have access to alternative sources of information for the official Soviet media to ignore embarrassing news. As a result, the Soviet media, to remain credible, are being forced to acknowledge, even if obliquely, some unpleasant news.

At the same time, the Soviet media has intensified propaganda campaign against foreign radio stations. The VOA and BBC are regularly denounced for slandering the Soviet Union. Deutsche Welle has been compared to the Nazi propaganda of Joseph Goebbels. Even Swedish raido has been attacked for alleged lack of objectivity.

The Polish events and reports about spreading strikes touch a most sensitive issue at a time when all of Eastern Europe is beginning to feel the full impact of world recession.

The Soviets and their allies have never stopped jamming to U.S. Financed radio stations based in Munich. Radio Liberty, which broadcasts to the Soviet Union, and Radio Free Europe, which broadcasts to the rest of Eastern Europe, have been attacked repeatedly for interferring in internal affairs of socialist countries in violation of the 1975 Helsinki accord.