> This is a patent, no one has actually made it, False. This has been in use by ad companies for quite a while now. One implementation, Silverpush, was reverse

> This is a patent, no one has actually made it, False. This has been in use by ad companies for quite a while now. One implementation, Silverpush, was reverse-engineered three years ago: https://www.theregister.co.uk/2015/11/20/silverpush_soundwave_ad_tracker/ https://www.theregister.co.uk/2015/11/20/silverpush_soundwav... And the company advertised it's services a year before that: https://techcrunch.com/2014/07/24/silverpush-audio-beacons/ https://techcrunch.com/2014/07/24/silverpush-audio-beacons/ More sources: 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... https://thehackernews.com/2017/05/ultrasonic-tracking-signals-apps.html https://thehackernews.com/2017/05/ultrasonic-tracking-signal... https://www.wired.com/2016/11/block-ultrasonic-signals-didnt-know-tracking/ https://www.wired.com/2016/11/block-ultrasonic-signals-didnt... https://arstechnica.com/information-technology/2017/05/theres-a-spike-in-android-apps-that-covertly-listen-for-inaudible-sounds-in-ads/ https://arstechnica.com/information-technology/2017/05/there...