Anan Wong was about to hit the snooze button one bleary morning when a radio report about audio books caught her ear. By the time the report ended, Wong, already a devoted fan of books on tape, had decided she would open an audio book rental store.

Today, her 3-month-old All Ears Audiobooks, located in a busy San Jose center across from Westgate shopping center, is humming. The $2 billion audio books industry is growing rapidly as Americans spend more time on the road stuck in commute traffic. Three-fourths of audio books are used in cars, according to the Audio Publishers Association, a trade group.

Though audio books have been around since Dylan Thomas recorded his poetry in 1952 for a book on tape, renting them has only begun to catch on. There are just a handful of Web sites and fewer than two dozen stores in the country that rent audio books, including two chain shops in the Bay Area, says Eileen Hutton of the APA.

All Ears is the only store of its kind in Silicon Valley. Since it opened in late July, about 530 customers have rented books on tape -- and 25 percent of those customers have purchased prepaid rental plans. If business keeps up, Wong expects her shop to be profitable in a year and a half.

Harmonious ride

Tracy resident Grace Boyer and her husband paid $99 for a three-month plan offering unlimited rentals. Boyer, an executive assistant at Hewlett-Packard, credits the tapes for creating more harmony on the couple's two-hour commute. ``We fight less if we've got a tape on,'' she says. ``I can't imagine driving back there without a book.''

Renting, particularly in these economically strapped times, is a compelling proposition. Audio books can cost as much as $80 for unabridged selections. Wong's store carries 5,000 titles for rent -- all handpicked by her -- and also sells audio books. Top sellers are mysteries, business titles and children's books. Nearly two-thirds of the store's customers are women in their 40s, which mirrors the demographics of audio book listeners nationwide.

Wong, a former software engineer, quit a high-paying job selling software and sunk more than $250,000 of her own savings to start the shop.

``You get days when it's really slow and you think, `What have I done? Am I crazy?' '' says Wong, a gregarious and relentless saleswoman.

But those moments, she says, are fleeting. She's happier than she's ever been -- working 90-hour weeks and having just enough spare time to munch on peanut butter sandwiches or noodle cups. ``This is my passion,'' says Wong, 31. ``I'm never bored here.''

Wong listened to her first book on tape in 1993, when she began traveling for work, and became addicted to reading business books. The tapes meshed perfectly with her hard-charging personality. She'd listen while she cooked, exercised or relaxed with her other hobby -- making greeting cards using rubber stamps.

Then one October morning in 1999, the radio came on. She heard ``audio books'' and sat straight up in bed. The timing was serendipitous. She was unhappy with her job, tired of the constant traveling and stress. ``I didn't want to be a part of the rat race anymore,'' she recalls. ``I wanted to do something on my own, something that had potential and would grow.''

So she planned and saved for 2 1/2 years. She also got her boyfriend to invest in the business as a silent partner. She visited audio-book stores in Texas and Atlanta. Without quitting her sales job, she also worked nights and weekends at a Barnes & Noble to learn what people were reading.

Revenue rising

Revenue for audio books outstripped printed books by more than 41 percent between 1996 and 2000, according to APA. Though there's no count of how many new titles are released each year, many publishers now ship audio books when printed versions go on sale. Almost any title, from bestsellers to classics to bodice-ripping romance novels to textbooks, is available in audio format.

Audio books are published on both cassettes and CDs. Most titles, particularly the unabridged versions preferred by many, still come on cassettes because each 45-minute tape holds a third more than a CD. Meanwhile, a few publishers are also offering downloadable MP3 audio books on the Web -- some at about half the cost of books on tape.

Wong's customers can be a picky lot. Ask about narrators and the discussion gets lively. Some hate men who try to do women's voices in high pitches, or women who try to imitate deep growls for male characters. Others, like schoolteacher Karen McCutcheon, only listen to tapes by narrators whose voices they like. She chooses books read by a handful of narrators who have lively and dramatic voices that ``catch the nuances.''

Fellow listener Rich Weeks agrees: ``There's nothing worse than a book read by an annoying narrator,'' he says.