Evothings

The Chromecast will soon enable authenticating nearby mobile devices using ultrasound. There is a JS library, sonicnet.js, that uses the Web Audio API to enable data transmission between devices using ultrasound (see the article Ultrasonic Networking On The Web).

This approach is interesting especially when working with refurbishing old tech that doesn't have e.g. a BLE radio. What other ideas do you have around using this method of device communication?

This "sounds" (haha) incredibly cool! Love refurbishing old tech.

How does it work? Is the regular speaker and mic of the device used then?

Any unwanted side effects? Like animals going crazy or something?

Using the display/camera to send messages could also work?

Boris Smus, the author of the sonicnet.js library, states that he tested his library successfully on Chrome-to-Chrome transmission on Mac Books, and between Chrome for Android and Chrome for Mac.

Good point about side effects. Boris states that the frequency range used lies within limits that children and non-human animals might be able to hear. I didn't try the library yet but I think that as long as the speakers and microphone supports it the frequency can be increased above the level which at least children can hear.