Transferring data using ultrasound

Question

Yamaha InfoSound and ShopKick application use technologies that allow to transfer data using ultrasound. That is playing an inaudible signal (>18kHz) that can b

Answer 1

You might have luck with a library I created for sound-based modems, libquiet. It gives you a handful of profiles to work from, including a slow "Ultrasonic whisper" profile with spectral content above 19kHz. The library is written in C but would require some work to interface with iOS.