Google Tone broadcasts URLs to any device within earshot

Google Tone is an experimental feature that could be used to easily share browser pages, search results, videos and other pages among devices in an office, classroom or family setting, according to Google Research.

While it can't pass through walls or travel beyond earshot, the system is designed to make sharing browser URLs as easy as talking to people nearby.

"The initial prototype used an efficient audio transmission scheme that sounded terrible, so we played it beyond the range of human hearing," researcher Alex Kauffmann and software engineer Boris Smus wrote in a post on the Google Research blog.

While microphones on laptops and video conferencing devices are optimized for the human voice, the extension incorporates a codec based on dual-tone multi-frequency signaling (DTMF), a system that has long been used in conventional telephony.

Tone works at low volumes and can be used over Hangouts, but it can be affected by speaker volume and microphone sensitivity.

When the extension is installed, an icon of a megaphone appears at the top right in Chrome. With the device's volume on, sharing a URL is done by clicking the icon.

Users have to be logged into their Google account, and their profile names and photos are displayed alongside the URL in incoming Tone notifications.

Tim Hornyak covers Japan and emerging technologies for The IDG News Service. Follow Tim on Twitter at @robotopia.