Heard any good books lately?

That question becomes increasingly important as busy Americans turn from reading books - a time-consuming process requiring the leisure to sit and concentrate - to listening to books reproduced on audio cassettes.Major publishers now release new books on tape as well as in conventional format. In October, Random House simultaneously released "The Queen of the Damned," the third novel in Anne Rice's vampire trilogy, in hardback and on two 90-minute tapes (an abridged version) read by actress Kate Nelligan.

Libraries see increased use of audio cassettes. "They're very popular," said Becky Robertson of the Memphis Public Library and Information Center. "In the past two or three years we've been emphasizing them because people want them, especially people who drive a lot."

People will listen to all kinds of books - mysteries, bestsellers, romances. "Even kids use them to listen to the classics," said Robertson.

The automobile seems to be the main arena for audio cassette listening. Most customers are interested in current fiction, she said. Interest is also high in self-help tapes.

The audio cassette industry is relatively new. Random House Audio Publishing has been in business a little more than three years, according to Leslie Nadell, director of publicity, promotions and advertising for Random House Publishing Group. There are now more than 300 titles on the backlist; 25 to 30 titles are introduced in two publishing seasons. The Random House program received a boost last year when the company acquired Warren Audio Publishing.

"Simultaneous publishing began about a year ago," Nadell said. "It's a way of really capitalizing on the publicity surrounding the release of a major book."

A typical audio cassette will be produced in an edition of 15,000 to 20,000 copies, "but it depends on the book. Every title is different," Nadell said.

Random House began by releasing books on audio originally published under its own imprints but has now expanded beyond the house. The company pays a licensing fee to the author or publisher of the book it wants to record on tape. Increasingly, Nadell said, authors are retaining the audio rights to their books, preferring to negotiate a 50/50 deal with the audio publisher themselves.

A company that made a smooth transition to audio cassette production is Caedmon, long a producer of records devoted to spoken literature. The company's list of records extended from Shakespeare plays to Dylan Thomas reading his own and others' poetry.

Caedmon has not only embraced the audio cassette business (beginning in 1971) but expanded its line into more popular areas. Audio cassette releases in October include Shakespeare's sonnets, read by Sir John Gielgud (two cassettes); Isaac Asimov's "Robot City, Vol. I: Odyssey," read by Peter MacNicol; and "Israel Is Born," described as a "documentary portrait celebrating Israel's 40th anniversary."

Contemporary subjects include "Shock Value," by cult filmmaker John Waters, and a series of self-help cassettes, like "Love, Medicine and Miracles" and "The Dance of Anger." In the spring, Caedmon will release an audio cassette of Erich Fromm's classic "The Art of Loving" and a sequel to "Love, Medicine and Miracles" called "Peace, Love and Healing."

Marianne Lordi, marketing services manager for Caedmon, now a division of Harper & Row, Publishers Inc., said Caedmon reaches beyond the Harper & Row imprint for its audio cassette titles. "Any publisher with appropriate work can be a source," Lordi said.

Depending on the popularity of the work involved, audio editions at Caedmon are published in numbers ranging from 7,500 to 30,000. The company's best-selling self-help cassette, "Love, Medicine and Miracles," now has 40,000 copies in print.