Thanks, very interesting. Basically the authors blast high-power (~92 dBA) ultrasound around 25kHz and hope that microphone non-linearities will overwhelm the audible signal.
This will sure make all the dogs in 20m radius mad. Hence the solution for the stealth recorder -- bring a dog, then complain about the ultrasound jammer (or at least to be aware of a jammer)
From the paper, it looks like the authors did not consider safety of animals, only human hearing safety.
As someone frequently annoyed by those stupid bird/deer/insect ultrasound emitters I hope this doesn't become common, with my luck I'll be able to hear them.
My neighborhood is full of these anti-social devices which are entirely designed to try to prevent dogs from shitting on their lawns. The noise they make is always at a pitch I can hear and my dog always ignores them.
My dog has no problem shitting on their lawns, and even sometimes pees on the devices.
So I'd like to find any actual devices which work on dogs (well I have no use for it but just to be sure they actually exist), because circa the original iphone I remember that there were apps which could reliably make its microphones do it (and impact dogs as expected).
Which country are you in? Here in GB it is expected that dogs will be under control, and in any case their owners are responsible for any damage they do. Cats on the other hand ... people have devices to scare away cats, though I'm not sure how well they work. Interestingly, cat owners have them in some cases ... to keep their own cat away from certain areas?
"My dog has no problem shitting on their lawns, and even sometimes pees on the devices."
Give him a treat from me, that made me smile. (I also hate those devices)