Anil Madhavapeddy

Context-Aware Computing with Sound / Oct 2003

While working as an intern at Intel Research Cambridge, Dave Scott and Richard Sharp and I put together a fun system based on the emerging new class of smartphones. The project kicked off when we randomly experimented with our fancy Nokia smartphones and discovered that they didn't have anti-aliasing filters on the microphones! We argued that

[...] audio networking can be used as the basis for developing context-aware applications. Audio networking allows standard devices fitted with speakers and microphones (e.g. PDAs, laptops, desktop PCs and mobile phones) to exchange data and infer information about their environment. One of the key advantages of audio networking is that it enables context-aware applications to be immediately deployed on a large scale without requiring users to purchase and install additional hardware.

We used the lack of antialiasing filters to create a set of inaudible location beacons that would allow laptop computers to simply listen using their microphones and discover their current location without any advanced equipment being required!

You can read more details in the paper or in the Ubiquitous Interaction Devices project page.