https://arstechnica.com/tech-policy/2015/11/beware-of-ads-that-use-inaudible-sound-to-link-your-phone-tv-tablet-and-pc/ https://arstechnica.com/tech-policy/2015

https://arstechnica.com/tech-policy/2015/11/beware-of-ads-that-use-inaudible-sound-to-link-your-phone-tv-tablet-and-pc/ https://arstechnica.com/tech-policy/2015/11/beware-of-ads-th... Not exactly the TV manufacturer doing it, but there have been reports of advertisers using ultrasonic pitches to do cross-device tracking.