Knoise is a co-monitoring service that tackles the problem of noise pollution in smart cities, in order to decrease the health effects that noise can have on citizens. By 2100, noise pollution will grow in cities and surrounding suburbs. At the same time, the concept of smart cities will likely be a common reality. In such a scenario, data will be exchanged between governments and citizens through active contributions to manage services efficiently. But how can smart cities deal with this foreseen change? 

The development of Knoise started with thorough literature research, expert user interviews, surveys, ethnographic research, and MVP testing. This first phase led to three crucial insights:

1. People currently are not aware of how noise can be problematic for their health, both physiologically and psychologically;

2. Perception of noise is not only based on quantitative data (as it is measurable through the decibel scale), but also based on personal perception and context;

3. To achieve a long-lasting change of behavior in people, it is needed to focus on different phases: awareness, motivation, adoption, and maintenance.

Following these insights as a guideline and through multiple iterations, the Knoise system includes: an awareness booth, in which users can learn about the effects of noise on themselves, a smart feedback system, which gently drives people to decrease their noise level in closed spaces, and a mobile application, that helps users monitor their own noise exposure and consult the noise map of the city, which is created thanks to both sensors around the city and users contributions. A version of the iterated MVP was finally tested by 30+ people, allowing the collection of numerous insights that confirmed the project's potential value while also giving valuable contributions to improving it.