Hidden audio is simply too easy. Hidden audio is the knife that kills desire for any financial services access through a voice assistant - for those smart enough to not follow the horde.
for me it kills all desire to have a voice assistant. I am already in the camp of taping over the camera's in my computers now will I need to worry about the microphone or what comes from the speakers? so the question is, shouldn't they be able to detect the wavelength of what they are processing to weed out some of the more obvious tricks? with voice recognition could it also not be limited to a voice it is trained…
iPhones already do this. My wife's iPhone won't respond to me, and vice versa.
Though I don't know if this is enough to mitigate the attack mentioned in TFA.