Ultrasonic on headphones, no sound



I have tried to listen the ultrasonic version on headphones (connected to phone) but I don’t hear any sound. Is it ok like that?
On the same phone I have tested on Frequensee:

  • on zero volume, the 20khz remains below -80db
  • on the max volume, the 20khz rise up to -40db
    I believe I have to set the volume somewhere in the middle…

I really would appreciate your experience regarding this,



Ultrasonic is silent. I wouldn’t listen to it at a max volume if you’re using headphones. I’d aim for -70 for headphones to be on the safe side.


I get it. Thank you!


I can hear it from my speakers on pc and from that distance my phone is showing -60db