Subliminal Talk

ok, so my speakers pass the speaker test for the ultrasonics and when I play them I can't hear them, however, when my 19 year old is here when I play them he says he hears a very high pitched ringing? he said its always there when the track is playing but it wavers in volume as it's playing.

I can't hear anything. Is his hearing just that much more sensitive? Any input would be appreciated as I can't play the ultrasonic tracks when he's around, he says it gives him a headache.

Thanks for any input.

Yes, younger people have a larger hearing range, and ultrasonic can cause them headaches as described. Lower the volume and it should be ok for them, or use headphones + masked tracks to listen instead.