Upscale movie theater chain Spotlight Cinema Networks is partnering with “audio beacon” company The Tone Knows (also known as TONE) to retarget and serve ads to moviegoers without distracting from the cinematic experience.

Launched in January, the partnership makes use of TONE’s unique “audio beacon” technology, which emits an inaudible tone that can be picked up by a smartphone and translated into “coupons, videos, retail partner graphics, links to incentives, and localized messaging directing consumers to nearby retail outlets,” according to press materials.

In the context of Spotlight’s 200 movie theater ad network partners, that means that moviegoers can opt in to receiving these messages by downloading the CineLife app after being prompted during the pre-show ads. If they accept, the tone is sent to their phones (the “sound” is embedded in the audio of the on-screen advertisement) and is translated into content at a later time. That time is usually a little after the movie is ended, so that customers have the chance to turn their phones back on and exit the theater.

TONE and Spotlight are currently in talks with a number of brands and retailers about locking down specifics, but Michael Sakin, president of Spotlight, told GeoMarketing that every test they’ve run, the program has “passed with flying colors.”