Theres no tone at 22.4KHz. It's a placebo thats caught peolpe out here already lol. There's a 21.1KHz tone but I very much doubt that people will hear it. Your dog will go crazy though.
Not the quality but the frequency range of the speakers. The speakers will reproduce frequencies higher than stated. They just start to roll of at certain octaves. Just turn up the volume.
The first 3 peak at about -1dB. The 4 tones after that peak at pretty much 0dB. The 8th tone peaks at -1dB. The 9th tone @ -4.5dB(less than half the power of the previous!). The 10th tone @ about -14.3dB and the 11th tone @ -33.3dB.
The 12 tone, as proved above, just isn't there.
No one will hear the 11th tone @ -33.3dB down! But through a very, very big audio rig!