444 DAYS: The Hostages Remember. By Tim Wells. Harcourt Brace Jovanovich. 469 pp. $19.95.

THIS BOOK may not be the final word on the Iranian hostage crisis, but it is about all one can absorb without risk of cardiac arrest. It is the strictly no-frills verbal testimony of 27 of the 53 hostages, stitched together by a few brief paragraphs to clear up the sequence of events.

There are even some voices missing, well- known to us at the time, like Katherine Koob of the Iran-America Society, who cheerfully reported from captivity two Christmases in a row that she had licked her weight problem. (Iranians with machine guns stood glaring just out of camera range, we learn, and food and gifts were snatched away as soon as the filming stopped.)

Those who do talk are not telling absolutely all. No CIA covers ae blown. The lucky six so daringly freed by the Canadians draw a veil over some details. (The ruse might be needed again.) It is not exactly clear when and how the Iranians got the combinations of the embassy safes, or how the news of the Canadian caper so swiftly leaked to the press.

But no gaps detract from the impact of the book. It is a document of tremendous power, not only in reconstructing events that were hidden from view at the time, but in revealing the infinite resilience of the human spirit.

The tone of forbearance leaves you limp. Hardly a voice is raised against the crackpot scheme that got them into the fix in the first place, or the 14 waffling months it took to get them out.

A howling mob of fanatics had already captured the embassy once, barely restrained by a chaotic political structure that had continued to disintegrate ever since. Twice charg,e d'affaires Bruce Laingen had been asked by Washington if he thought admitting the shah to the United States for medical treatment would endanger embassy personnel in Iran. Twice he had responded that it would. So much for a second opinion. The shah was flown to New York in a private jet. In Iran, the howling mobs added "Death to America!" to their cries of "Death to the shah!" and the embassy paid the price.

Press attach,e Barry Rosen minces no words. "I very strongly felt that the decision was at variance with all of the objectives we were working toward in Iran and was at variance with our national interest. In addition, it jeopardized our personal safety. It was the sort of decision that signaled to the Iranians that we were attempting to overthrow the regime and return the shah to his throne."

Captivity took its toll. At least one hostage went bonkers and attempted suicide by hurling himself at a wall; another told the Iranians the names and duties of his fellow captives to gain better treatment for himself. Both are mentioned, but not dwelt upon -- one with sympaty; the other with rage.

Their emotional stability in the face of threats, mock executions and near starvation defies all logical limits. Just tie me to a chair for 24 hours and take my toothbrush away and I'll sign any paper you want. These people stayed roped to chairs, blindfolded, for weeks at a time; they survived solitary confinement, unheated jail cells, wormy food and filthy plumbing for weeks and months on end without losing their dignity or spilling the beans. If an opening occurred, they got in a few jabs of their own. They stopped up sinks, blew fuses, used Geritol capsules as sling-shot pellets, which drove their captors wild.

How did they endure? Seeking the sources of their strength is one of the fascinations of the book. Knowing Farsi ranks high on the list. Shockingly few of the captives had even a beginner's grip on the language of the land they were assigned to. Withholding information was their captors' strongest ploy. Prisoners who knew Farsi could crack this barrier, and had the strength of 10. One political officer, fluent in Farsi, hid a radio in his pillow and smuggled news bulletins to his colleagues through a crack in the wall of his cell. The six the Canadians helped to escape owe part of their rescue to the fact that chief political officer Victor Tomseth could speak Thai and communicate safely with a Thai who (risking his own neck) helped conceal them until the Canadians took them in. Two who spoke Arabic and French could glean from the Algerians that they were soon to be released, which the Iranians denied to the end.

They were also professionals, and no one had promised them a rose garden, especially in Iran. The military had specific POW training to draw on. The others had more than a passing knowledge of evasion techniques. They prepared ahead for questioning; they watched for openings; they babbled irrelevantly. After one marathon interrogation, with guns put to his head, the army attach,e was left with pen and paper to confess his role in Vietnam. He had reached page 37 by the time his tormentors returned, and was barely beginning to describe his sophomore year in high school. ("Oh God, they got upset about that.")

RAGE was a weapon. Most of them stayed mad at their captors from beginning to end. They mistrusted them, scorned them, hated them and pitied them by turns. Army medic Don Hohman, the acknowledged champion hater, went on two hunger strikes and cursed fervently every "rag head" he saw for all 444 days. "Different people react to captivity in different ways," he says. "I was raised on the streets and I reacted to them the way I would've reacted to any punk on the streets." Faced with stubbornness and fury, the guards would often back down.

Their resourcefulness boggles the mind. They measured and paced their cells; kept records of their days; rationed their time, studied, read, played chess, made a coffee stove from a discaded tin can. Two of them wangled brushes and paint and redecorated their cell.

Although their captors tormented them, taunted them, beat them and kicked them in the groin, they didn't want them dead. As communications officer Bill Belk puts it: "If hostages started turning up dead, they were afraid that President Carter would level the whole damn country. Just remove Iran from the map." Their greatest danger, one military hostage felt, was that their guards could not protect them from the even more fanatic zealots who were chanting in the streets for their blood, or that they'd be accidentally shot as their untrained captors kept waving their weapons around.

In the end, as their treatment got worse after the abortive rescue attempt, the fact that they had survived to that point became positive reinforcement of sorts. "After all of that I started feeling like a survivor," one says. "I realized a lot of things about myself that I'd never known before. I was more aware of my fiber. I'd never really been tested before, but in Iran I felt like we'd all been tested about as much as an individual can be tested . . ."

Ironically, the ultimate test came after they were free. Numb and euphoric they were flown to Algiers. Still dressed in the rumpled rags they'd worn for more than a year, they watched smartly clad officials congratulate each other for securing their release. At the U.S. military hospital in Wiesbaden, they ranged the halls in hospital gowns, as teams of doctors, nurses, dentists and psychiatrists pursued them with drills, needles, questionnaires and specimen bottles at every turn. They knew how to set limits by then, and began to pour grapefruit juice in the specimen jars.

The heroes' welcome at home was more than they could endure. Nothing prepared them for the outpouring, and they had a disturbing feeling that their countrymen had missed the point. "I think the kind of attention that we were subjected to when we came home was more damaging to me than anything the Iranians did," said one. "People were trying to turn me into a hero, and I didn't feel like a hero. I felt more like a victim, and a survivor. But not here."