Former president Richard M. Nixon lost another Supreme Court case yesterday when the justices refused to restrict public access to 6,000 hours of Oval Office tapes.

The court acted without comment and without dissent, letting stand a lower court decision that also went against the former president, who argued that only transcripts or summaries should be released to the public or that access should be delayed until the participants in the conversations are dead.

The tapes could be made available for listening by 1984 or 1985. They cover 2 1/2 years of the Nixon presidency before the existence of the taping became public during the Watergate investigation in June, 1973.

Nixon still has the right to challenge the release of individual tapes he considers too personal.

Tapes used in the investigation of the Watergate scandal have been available for listening at the National Archives on a daily basis. The 880 tapes at issue yesterday cover 6,00O hours of conversations of "general historical significance," whether or not they relate to Watergate.

They could shed new light on such subjects as the Vietnam war, the 1972 presidential campaign against George McGovern, the aftermath of the Kent State shootings, relations with national security adviser Henry A. Kissinger, events leading up to the resignation of Vice President Spiro T. Agnew and virtually every important decision made in the Oval Office during the 2 1/2-year period.

The recordings are so extensive that it would take an individual three years of eight-hour days and five-day weeks to listen to them all.

If the tapes follow the pattern of the 31 already released, they could also include expletives, ethnic slurs and candid assessments of numerous people in high places.

While the material will be screened by archivists for national security and private information, the law mandates release of any materials "essential to an understanding of abuses of governmental power."

Nixon's lawyers had argued that the privacy of a president must be protected when he "retreats behind the doors of the Oval Office to discuss with a congressman, or a private citizen, or staff member, their ideas concerning potential legislation, a pending election, the menu for a state dinner or the conditions of the country generally."

Nixon now has a 1-3 won-lost record before the court, which includes four Nixon nominees. Last year, the court granted him his sole major victory when it ruled he was immune from a money damages suit brought by Pentagon whistle-blower A. Ernest Fitzgerald, who was fired from his job during the Nixon years.

But Nixon lost his attempt to block the Watergate prosecutor's access to Watergate tapes and in 1977 the court ruled against him in his fight to retain custody of the tapes and documents not related to the Watergate prosecution.

Yesterday's case (Nixon vs. Carmen) represented his challenge to some of the regulations for public access, particularly provisions allowing people to listen to the tapes. The General Services Administration issued the regulations following the 1977 court ruling.

The former president argued that the "manner and tone of his personal expressions" should remain private by having only transcripts or summaries released.

The government said that careful screening by archivists could protect Nixon's legitimate claims of privacy. In addition, Nixon "or any other person claiming a constitutional or legal right" can challenge public access on a tape-by-tape basis.