Cross-Device tracking

[Morla]

So I read about Cross-device tracking and one of the methods used involves ultrasonic sound being emitted through TV and received by rogue android apps. I think this could be a reason to put a filter in place to remove everything >20khz?

 

[Philbo King]

Frankly, most users could cut everything above 10k. That last octave doesn't contribute much anyway, assuming you can hear it at all. To see for yourself, try cutting everything below 10k. Not much going on, usually.

 

[unpluggged]

I think this could be a reason to put a filter in place to remove everything >20khz?

Yes, here is an example of such a filter (must be connected to ground to work):

ultrasonic sound being emitted through TV

Emitted how?

and received by rogue android apps

Received how? And why not by rogue iOS apps?

On the scientific value of the paper the linked Wikipedia article is based on, all I can say is to quote this passage:

We create ultrasonic beacons that cover different frequencies, lengths and sound levels. In particular, we choose frequencies between 18 and 20 kHz

I think it says it all about the competence of its authors.

 

[Morla]

On the scientific value of the paper the linked Wikipedia

So you wanted to say it's not real at all? The actual paper from a german University

https://intellisec.de/pubs/2017a-eurosp.pdf