Using a microphone to create a 3D map of Lausanne Cathedral.
Photo courtesy LCAV / EPFL Using a microphone to create a 3D map of Lausanne Cathedral.

Architecture's influence on sound—particularly in the case of acoustical performance spaces—is a deeply appreciated phenomenon. In a typical design process, architects and acoustic consultants attempt to anticipate the complex effects that architectural spaces and materials will have on sound.

As researchers at the EPFL (École Polytechnique Fédérale de Lausanne) have recently demonstrated, the process can also be reversed. Inspired by the way that bats and other animals employ echolocation to "hear" their physical surroundings, professor Martin Vetterli and his team from the Audiovisual Communications Laboratory (LCAV) have created a computer algorithm that generates three-dimensional architectural maps using only auditory information.

After placing four microphones in a physical space and making an audible sound, the software will construct a virtual model of the room to a tolerance of just a few millimeters. The software doesn't require the microphones to be placed in particular locations; it simply interpolates between the original sound and the echoes received by each microphone to create its spatial map. Although the algorithm is most effective in simple, convex spaces, the scientists attempted to map an alcove at the Lausanne Cathedral with some positive results.

Potential applications range from design to forensics. "Architects could use this to design rooms—for example concert halls or auditoriums—based upon the specific acoustics they would like to create," said doctoral student Ivan Dokmanic in an EPFL press release.

Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.