HEAR that high-pitched ringing? No, me neither. But such sounds at low volume can now be used to deliver bonus television content to your cellphone or tablet.
鈥淚magine that you鈥檙e watching a travel programme and your phone instantly receives the exact location, booking details and nearby attractions of the place you see,鈥� says Tae Hyun Kim of in Seoul, South Korea which developed the technology.
The system uses your TV鈥檚 speakers to play data-filled tones alongside whatever you are watching. You won鈥檛 notice a difference, but the microphone on your smartphone will, picking up additional content streamed alongside the main event. 鈥淭his can make television interactive,鈥� says Tae.
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This use of ultrasound is already possible, but the volume levels break broadcasting rules and can irritate young people or animals. 鈥淭he real advantage of our system is that its noise level is the same as a quiet library,鈥� says Tae.
Soundlly鈥檚 focus is currently on second screens such as your phone or tablet, but the technology could be used to send data between any two devices that have speakers and microphones, says at the University of Northampton, UK. 鈥淯sing ultrasound, devices can literally talk to each other.鈥�
This article appeared in print under the headline 鈥淪ilent squeals make TV interactive鈥�
