Not many people are pondering how a 21stcentury gadget such as the iPod might be integrated into the ancient practice of yoga. But Jonathan Fields is. A self-confessed “technology geek,” the founder of the Sonic Yoga fitness studio views the incorporation of science – be it color theories or the latest incarnation of the Walkman – as integral to bringing yoga to larger audiences.

“Is there a way that we can use technology to noninvasively enhance the practice?” Mr. Fields asked rhetorically. Since the studio’s founding in November 2001, the various answers he’s put forth have argued that strategic lighting and sound manipulation can enhance the individual’s stretch while, simultaneously, television and the Internet can expand the exercise form’s reach.

The iFlow class is his latest experiment. Starting in mid-October, at designated time slots, intrepid students at his studio will be provided with MP3 players loaded with yoga instruction instead of music.

“You can pick the level of the class and the teacher you practice with here for $4.95,” he said.

Recorded guidance is then delivered via armband-attached listening devices programmed with 50 different classes. As a result, myriad levels are able to cohabitate unobtrusively in whichever of the two studios is going unused during the odd hours: either the yellow-walled 600-square-foot space upstairs or the larger 1,000-square-foot space with moss-green curtains downstairs.

Ensuring good karma with his staff as well as his clientele, Mr. Fields will pay his teachers a residual each time one of their recordings is used. Meanwhile, students wishing to take their practice home will have the additional option of downloading the tracks from Sonic Yoga’s ever-evolving Web site (www.sonicyoga.com). The exact fee for online usage is still under discussion, but currently Mr. Fields and company are leaning toward a free introductory offer accompanied by a minimal fee for each additional download.

The evolution of one-on-one audio instruction actually harkens back to an e-mail questionnaire that Mr. Fields sent out some time ago. After reading hundreds of clients’ responses on how they used DVDs and videotapes, he learned that “the vast majority of people said, ‘We don’t watch the video, we just listen to it.'”

Admittedly, a strictly audio tutorial is not without its limitations. IFlow tracks presuppose a solid understanding of yogic terminology. And, as a concession to most students’ initial reliance on visuals, cue cards of stick figures illustrating the stances will be available along with the MP3 players at the front desk. Even so, because of the restrictions that accompany primarily spoken instruction, the pacing of iFlow can be slower than Sonic Yoga’s more typical vinyasa practice, which is decidedly rigorous.

Consistent with other Sonic offerings, some iFlow recordings layer New Age background music with subliminal sound waves intended to induce states of consciousness – energized, meditative, or balanced, depending on the class.

“Brainwaves are affected by different frequencies,” said Sonic Yoga co-director Lauren Hanna, who said she has used one of the more soothing sound pulses to help calm her for a visit to the dentist.

Aural manipulation of the subconscious has long been a hallmark of the studio’s methodology. (Hence, the name.) Its signature Theta Flow class is a modified yoga regimen that not only makes use of psychoacoustics but looks to trigger mood changes by lighting early portions of the class in red for stimulation, then progressing through the entire color spectrum until the room is bathed in violet, a color believed to be advantageous for relaxation.

Theta Flow was discontinued this September as its audiovisual devices were integrated throughout the course schedule. At the studio’s solstice/equinox rave yoga parties for instance, midnight revelers wearing glow-in-the-dark jewelry may receive nonverbal suggestions buried in trance music as instructors sporting wireless headsets take them through fast-and-furious asanas.

Perhaps the most low-tech Sonic Yoga gets is in its weekly, one-hour class for cable access that started this spring. (The show, edited by Mr. Fields in his office, airs Thursday mornings at 7 a.m. on Time Warner’s Channel 56.) Silent except for the voice of the instructor and the collective sighs of the students, this videotaped lesson nevertheless remains indebted to electronics – using airwaves instead of radio waves.

Sonic Yoga also carries recordings and DVDs of it classes. “Turbo Flow” ($19.95), for example, is a DVD of a highly aerobic sequence of postures recently verified by Adelphi University’s Human Performance Lab to serve as an effective weight loss regimen. Throughout the routine, participants were shown to burn 5 to 9 calories a minute.

With a lengthier teacher-training component to be instituted in 2005, Sonic Yoga aims to expand its reach. Ms. Hanna, who helms the Yoga Alliance-certified training program, sees future graduates as teachers equipped to open studios of their own, a franchise approach akin to the highly successful Bikram Yoga. Already this fall, the first wave of new Sonic Yoga studios is expected to surface in three different locations: Park City, Utah, Harrison, N.Y., and a third site in northern New Jersey.