sonic surrounds

Pursuing a suspect through an underground tunnel or cave is dangerous work for the police or military. But a system being developed at the University of Denver, Colorado, US, could make their lives a whole lot easier. Revealed in a recent patent finding, the system uses faint sound resonances to build a map of a hidden chamber and locate anyone hiding inside.

Low frequency noise – between 1 and 200 hertz – is fed into the tunnel from a loudspeaker placed at its mouth. The cavity will then resonate at different strengths and frequencies depending on its shape. A microphone detects these resonances and a connected computer converts the audio information into a map showing the size and shape of the chamber on a screen.

If anyone is hiding inside, their movement should alter the reflection pattern and thus changes the resonant spectrum. Tests show that the system works even when the person hiding is just 1/500th of the volume of the entire chamber. And the system should get more accurate with the creation of a database of resonant patterns relating to different cavity shapes.

Read the cave mapping patent here

via http://www.newscientist.com/blog/invention/2005_11_01_archive.html

neoscenes.net is a travelogue website (and also the pseudonym of John Hopkins), that states its goal to become “a holistic examination of nomadic movement at the turn of the millineum.”

Apparently, I use some neoscenes content in my soundtransit composition….
“…a neoscenes sample starts things off, and there are several other neoscene samples mixed into the 40 minute broadcast made on 23 April. nice!”