Ultrasonic Cross-Device Tracking: A Consumer Management Tool with FTC Warnings

A consumer's television or computer may be emitting silent signals that her smartphone can hear, recognize and answer back, but the consumer can't sense them at all. These signals are telling retailers about their customer's habits and technology, but using the signals without appropriately informing consumers could land the retailer in hot water with the FTC.

Ultrasonic cross-device tracking technology finds and follows specific consumers through the use of embedded ultrasonic tones. These high frequency tones, which are silent to the human ear, can be emitted by advertisements, billboards, web pages, radio and television broadcasts, and even physical locations like brick-and-mortar retail and sports stadiums. Almost any device microphone, such as those in a mobile phone, can be enabled to detect the ultrasonic tones, and almost any device speaker can be used to respond to the tones.