shannon ultrasonic showing up as 17,000hz on all devices from ipad to speakers. help

[Xebec]

shannon u said u need minimum 20,000hz to run ultrasonic

but all my devices from the tv, ipad mini(stereo speakers) and speakers are showing it at 17,000hz when measured by frequensee

so will my mind hear the ultrasonic on my devices?

thanks

How are you measuring the requencies coming out of your devices?