Tone is an experimental Chrome plugin from Google Research that lets computers share small amounts of information (like URLs) with ultrasonic chirps.
There's something indefinably interesting about this — in theory, it's less work than setting up a Bluetooth connection and less cumbersome than joining an email thread or IM session to share information with small, ad-hoc groups. But in part, that's because this has no security or access control. However, if this matures to the point where it's used to share sensitive information, you can imagine that it would acquire all the tedium of Bluetooth pairing (now that's "tone policing!". But in the meantime, the fact that it's acoustically limited (doesn't easily penetrate walls or travel far) feels like there's something new and useful there.
Tone provides an easy-to-understand broadcast mechanism that behaves like the human voice—it doesn't pass through walls like radio or require pairing or addressing. The initial prototype used an efficient audio transmission scheme that sounded terrible, so we played it beyond the range of human hearing. However, because many laptop microphones and nearly all video conferencing systems are optimized for voice, it improved reliability considerably to also include a minimal DTMF-based audible codec. The combination is reliable for short distances in the majority of audio environments even at low volumes, and it even works over Hangouts.
Because it's audio based, Tone behaves like speech in interesting ways. The orientation of laptops relative to each other, the acoustic characteristics of the space, the particular speaker volume and mic sensitivity, and even where you're standing will all affect Tone's reliability. Not every nearby machine will always receive every broadcast, just like not everyone will always hear every word someone says. But resending is painless and debugging generally just requires raising the volume. Many groups at Google have found that the tradeoffs between ease and reliability worthwhile—it is our hope that small teams, students in classrooms, and families with multiple computers will too.
Tone: An experimental Chrome extension for instant sharing over audio [Alex Kauffmann and Boris Smus/Google Research]
(Image: Listen for Tone,
Jeramey Jannene, CC-BY)