'Seeing' with sound: There's an app for that
What is it like to be a bat? As Thomas Nagel persuasively argued in 1974, we will never know for sure to navigate mainly by sonar, but a team of researchers could soon bring us the next best thing: an app for that.
In a study published in the current edition of the Proceedings of the National Academy of Sciences, scientists at Harvard University and the聽脡cole Polytechnique F茅d茅rale in Lausanne, Switzerland, describe how they have developed a software algorithm that using just four microphones and a snap of the fingers.
The microphones pick up the echoes of the snap as they reverberate off the room's walls, and the algorithm measures the tiny lags between the sounds to measure the distance of the microphones from the source of the sound, as well as the distance from each of the walls.聽
鈥淥ur software can build a 3D map of a simple, convex room ,鈥� says Ivan Dokmani膰, an 脡cole Polytechnique F茅d茅rale聽doctoral聽student and the study's lead author,聽in a press release.
The researchers first tested their algorithm in an empty room with a movable wall. Pleased with the results, they moved on to something more ambitious: mapping an alcove in the Lausanne Cathedral, a floridly decorated Gothic church. The press release describes their efforts as聽yielding聽"good partial results."
In addition to helping us better identify with our聽chiropteran cousins, the researchers' algorithm promises a wide range of applications.
"Architects could use this to design rooms 鈥� for example concert halls or auditoriums 鈥� based upon the specific acoustics they would like to create,鈥� says Mr. Dokmani膰.
