THE VOICE is intransigent, unmistakable. It is Mercedes McCambridge -- famed radio actress, Oscar winner, recoverd alcoholic, survivor of an attempted suicide, voice of the demon -- speaking to us in an autobiography so eccentric and stylized that one comes away depelted, disoriented.

This whirlwind memoir, which is a series of impressionistic set pieces, each one progressively more bizarre than the next, begins with the author in London sobbing at the feet of the statue of Shakespearean actress Sarah Siddons and grieving for her "dead dreams" and lost hopes." It ends in Dubuque as she climbs nude into a bed recently vacated by a dead nun, now "wrapped in mystic communion with the shy visitor Emerson calls God." The actress, best remembered for her intense performances as Rock Hudson's sister in Giant and as Elizabeth Taylor's mother in Suddenly Last Summer, approaches these vignettes without humor and as if they were acting problems, attacking them with the characteristic theatricality and morbidity that has always marked her film efforts.

We are introduced to her actress-like mother ("Iambic pentameter was not her meter") and to Cousin Matt, an undertaker whose customers lay right under where one ate breakfast. The young McCambridge accompanies a nymphet classmate to a backstreet abortion then to a hotel where the girl almost dies. (This is just one of the many, often grotesque, soliloquies on fetuses and stillborn children.) Later, when she harangues a group of motion picture executives for the disgraceful treatment actors received during a cattle call audition, she is met with immediate applause and is rewarded with a role in the film version of Robert Penn Warren's All the King's Men, for which she wins the Academy Award for best supporting actress.

As one melodramatic stroke follows another, it becomes clear that McCambridge is not writing a traditional show business biography: the usual behind-the-scenes gossip peppered by various off-screen sexual adventures. She has something more substantial in mind. But the execution is another matter, and one must piece together the smattering of biographical data oneself.

What she goes offer is her philosophy, poetry, pipe dreams. On the subject of a mother's penchant for upstaging her daughter, for example, we get this interesting bulletin: "Thine own mother is using up all the oxgyen; thou art left bereft in a vacuum. It is probably just as well that Garbo never had a little girl." Dramatic poems on the Irish woman and a fantasy on the apocalypse soon make special appearances. As Orson Wells says to her one night in Carefree, Arizona: "You are gloomy, you are intense, and you are thoughtful. Now stop all three."

Undaunted, she continues,: "So many people have told me that I am a funny person, that I say and do funny things. They say I have a zest for life. They are so wrong." This is from a woman who confesses to a childhood hobby of chicken killing, swims naked in the Mediterranean at midnight, looks straight into the eyes of Pope Pius XII and lies, says that "Death by copulation is not for me," and admits spending her evenings at McDonald's, slapping her thigh with glee at a good book.

By the time the busy actress gets around to discussing her career, which is intermittently, her self-dramitizing has gone beyond camp. (Even a frightened minature poodle, whom her dog, Sir Malcolm Percy, has taken a fancy to, is labeled a "strumpet.") She is both malevolent and gracious to her supporting cast, and her generosity is especially touching when geared toward kindred spirits James Dean and Montgomery Clift. As for the well-publicized antagonism between Joan Crawford and herself during the filming of Johnny Guitar, McCambridge says she doesn't want to get into the unpleasantness because she herself is "a very nice person." A few sentences later, she is commenting on Crawford's need for "sweat spray" and the star's willingness to be photographed outside "only in long, long, long shots."

Some nice person.

McCambridge fully discusses her work on The Exorsist, when she was used to dub in the voice of the demon because of her considerable experience of radio soap opera and Orson Welles's Mercury Theater.

But McCambridge would rather avail herself of various crusades as she does in a excellent section on alcoholism -- a subject she has lectured about across the country.

The Quality of Mercy is finally a baffling book, evangelic is nature and uneven in quality. Page for page, it is the most unusual and ambitious celebrity memoir in years. And not all of that is due to the author's propensity for capital letters, italics, exclamation points (10 in a single paragraph!), imaginative slang and sentences which fail to plug into any kind of grammatical or dialectic socket. But, if the point of the memoir is to distill one's experience, this book is a weird kind of triuimph.

This tough gutsy woman exposes herself to ridicule, gets into some rough psychological terrain and still comes up uncompromised -- a survivor. With emphasis on religion (the bleeding Jesus imagery, the odd ridicule of born-again Christians, the evangelic stances) she is saying this world is a stage and self-expression is her religion. Some will be amused by her unrelentingly gloomy story and its sour, recurring theme: "Life is a bitch." Others will take some of its inspired nuttiness and bag-lady wisdom as gospel. The experience is somewhat like holding the hand of an old friend while he or she talks all night on the Truth, sin and loss. It's exhausting but quite rewarding in a good-book, thigh-slapping sort of way.