What do the sounds of a city tell us about the quality of the environment–say, how much traffic there is, how smoothly it’s running, and how noisy it can get? What do sounds indicate about the presence of wildlife or the happiness of people?
These were all questions taken up by the Ear-It project. The E.U.-funded research–part of a wider smart city pilot in Santander, Spain–looked at what role sound analysis might have in city management.
Pedro Maló and his team developed five Acoustic Processing Units and placed them in “strategic” areas of the city. “It is a hardware and software computer, with some microphones, software framework for acoustic event detection and maths flow estimation,” the researcher says. Here are possible applications Maló has either experimented with, or sees as possible in the future.
The team tested the sensor’s ability to count cars and found it produced “comparable” results to the typical cable-in-the-road method. And, Maló says his sensors are easier to install: “You don’t have to drill in the road drill the road, and if you use lots of them, you can estimate traffic to a large scale.”
Maló positioned one unit outside a city’s hospital, proving it could identify ambulances, fire trucks etc, and potentially help with traffic management. “We can change the traffic lights in order to fast track the traffic that is close to the ambulance and move forward the vehicle,” he says. See more in the clip here:
Several U.S cities are now using ShotSpotter, an acoustics system that helps locate and identify gunfire (by triangulating the sounds).
“We don’t use it as much in Europe. But you have that in the U.S.,” says Maló. “It is not only identifying the gunshots, but also the type of gun–repetition, single shot, military, personal use, whatever.”
Here’s a promo from San Francisco:
Why not use sound analysis to count wildlife and gauge how green the environment is becoming? (And perhaps even identify species like this new “Shazam for birds” on Kickstarter).
Cities measure city noise volumes by “driving a truck around for two or three days and creating a wider model based on that.” Which doesn’t tell you much. (It doesn’t, for example, account for outstanding events, like a football game on Saturday). For further research, Maló wants to develop sound maps for cities using his technology (which he thinks is better than a mobile phone-based system like the one we wrote about here).
More broadly, we could also use sound analysis for deeper questions, the health and well-being of an area over time. That would surely be a nice addition to photos, video, and smell maps.