What frequency are these apps using? I haven't looked it up but I doubt most computer speakers go above 15Khz (why would they?) A young person should be able to hear really high but audible tones and an adult would rapidly lose the ability. If this is not the case it would make sense to set a limit on the tones such a device can send and receive.

On the other hand there might be legitimate uses for such tech so maybe better to have it as a security option to send and receive ultrasound per individual, i.e. if I can't hear above 10khz maybe I can set my audio to not send or receive above that without app specific permission