LISNR

LISNR transmits encrypted data over inaudible ultrasonic sound waves, which do not require line-of-sight the way QR codes do or a specialized antenna like NFC. The protocol works through walls, in loud environments, and on devices manufactured as far back as 2011. For automotive applications, it can unlock a vehicle even when the phone is in a pocket or bag, which Bluetooth Low Energy struggles with in the same scenario.

Visa has publicly piloted LISNR's ultrasonic push-payments protocol for tokenized transactions. Separately, Jaguar Land Rover integrated LISNR into its walk-up vehicle access system. The company also supports live-event ticketing and building access vendors, though end-customer names in those verticals are often client-confidential.

No custom hardware is required — LISNR's protocol uses the standard speakers and microphones already embedded in smartphones, point-of-sale terminals, and vehicle infotainment systems. The company licenses a software development kit (Radius SDK) that enterprise developers embed into their existing applications to enable ultrasonic authentication.

Yes, LISNR is venture-backed. Visa invested in the company in 2019. Earlier rounds included participation from Intel Capital and other technology-focused investors. The company has not disclosed total funding figures in recent years, and it operates as an independent entity headquartered in Cincinnati.

LISNR's transmissions are encrypted using standard tokenization frameworks — analogous to what a mobile wallet uses for NFC — but over an ultrasonic carrier. The token is short-lived and single-use, so even if captured, it cannot be replayed. Additionally, because the frequency band is above human hearing and the payload is small, pattern-based interception requires physical proximity and specialized acoustic equipment, which the protocol's time-to-live signature is designed to defeat.