The Soviet Union issued its sharpest attack on the Voice of America today since this country stopped jamming the U.S. government broadcasts three years ago.

In an article noting the VOA's 35th anniversary on Thursday, Tass commentator Yuri Kornilov said the radio, which broadcasts in several Soviet languages, has become "one of the most powerful mouthpieces of American imperialism." He reserved particular criticism for coverage of the activities of Soviet human-rights activists.

"It raises a hullabaloo round mythical 'human-rights infringement' in the U.S.S.R. and other socialist countries, concocted in the kitchens of Western propaganda centers," Kornilov wrote.

The VOA has been regularly reporting the growing controversy between the United States and the Soviet Union on human-rights questions as the Carter administration has focused on the issue. This coverage has included the activities of Soviet dissidents.

Soviet radio and newspapers in recent days have given prominence to an increasing number of articles on alleged human-rights infringement in the United States.

The Tass commentary did not directly threaten to resume jamming VOA broadcasts, which the Soviets stopped in September 1973 at the height of detente.

The language of the commentary, however, was similar to attacks regularly leveled at the Radio Free Europe and Radio Liberty, U.S.-sponsored stations that broadcast to Eastern Europe and the Soviet Union respectively. Both stations are frequently jammed.

Today's harsh commentary has been preceded by a build-up of less intense attacks over the past two weeks. Western observers in Moscow noted that these attacks usually have been in articles or broadcasts meant for foreign consumption.

In other developments in the Soviet Union and Eastern Europe:

Tass ridiculed Western news reports of microwave radiation at the U.S. embassy in Moscow, calling them a part of a campaign to worsen U.S.-Soviet relations.

Soviet human-rights activist Ludmila Alexeyeva emigated from the Soviet Union with her husband and son. They have exit visas for Israel but hope to settle in the United States, friends in Moscow said.

Romanian Deputy Prime Minister Cornel Burtica met with dissident leader Paul Goma in an effort to cool the country's human-rights campaign, according to Western diplomatic sources interviewed in Bucharest by UPI by telephone from Belgrade, Yugoslavia.