Welcome to Hush City!


Hush City’s icon (C) Antonella Radicchi 2017

Click here to download Hush City app on iTunes store!

Click here to download Hush City app on Google Play store!


Hush City is a free, citizen science mobile app, which empowers people to identify and assess quiet areas in cities as to create an open access, web-based map of quiet areas, with the potential of orientating plans and policies for healthier living, in response to issues framed by European environmental policies (e.g. the EC END 49/2002).

Our cities are becoming noisier by the hour. Only in Europe, over 125 million people are affected by noise pollution from traffic every year (EEA 2014), and apparently, quietness is becoming a luxury available only to a few of us. By using this free mobile app, you will contribute to making quietness available to all those who appreciate it and you will generate open data, which can be exploited by policy makers and planners to monitor and protect the quiet areas crowdsourced.

Hush City app will help you to identify, access and evaluate everyday quiet areas in your neighborhoods. You can find places such as small, quiet spots where you can go to escape the city’s chaos, relax, read a book, play with your kids, and have a pleasant conversation.

Launched in 2017 within the context of a pilot study in Berlin, Hush City has scaled up to the international level and it is now used internationally. The Berlin Senate has also used it within the context of the Berlin Noise Action Plan 2018-2023.

Join the Hush City community. It is simple!

  • Download the free Hush City app and install it on your smartphone
  • Go to one of your favorite quiet places
  • Launch the Hush City app and click on the botton “Map the quietness around you”
  • Record the sound of the quiet place where you are and measure its sound levels*
  • Take a picture of the place where you recorded the sound
  • Answer the questions addressing the environmental quality of this quiet place
  • Share this information with the Hush City community.

Or, use the app to find a quiet spot near to you. Go to it and enjoy spending some time there.

* Please be aware that noise levels measured by the mobile app, may not be entirely accurate, depending on which smartphones are used, weather conditions and other factors.

Main features of the Hush City app

Using the Hush City app, you can:

  • Crowdsource  your favorite quiet areas and share them with the Hush City community;
  • Identify and access quiet areas in your city or in other cities worldwide, shared by the Hush City users;
  • Filter the quiet areas according to their sound levels, descriptors used to tag them, quietness, visual quality and accessibility, as perceived by the users who crowdsourced the quiet areas;
  • Share the quiet areas via social media;
  • Review your personal surveys and delete them anytime without justification;
  • Become a Hush City Ambassador;
  • Give feedback on the Hush City project.

Hush City Map

The quiet areas crowdsourced with the Hush City app are open access and available on line via the Hush City Map.

Impact of Hush City 

Hush City is included in the EC Joint Research Centre Technical Report (Ponti & Craglia 2020) among the European citizen-generated data projects impacting public policy.

As a citizen science analytical tool, Hush City is featured in the WHO/UN-Habitat Sourcebook (Grant et al. 2020) Integrating health in urban and territorial planning.

Hush City is adopted by the City Councils of Berlin (2018) and Limerick (2020-2021) within the context of creation of the Quiet Areas Plans.

Full list of Press Coverage is available here.


2019 Prix BLOXHUB Interactive, Category: Excellence, Honorary mention. Theme: “Making Urban Space More Liveable Using Digital Technology”.

2016 Falling Walls Young Innovator of the Year Award, Finalist.

Credits & Acknowledgments

Hush City has been invented by Dr. Arch. Antonella Radicchi.
The Hush City’s idea originates from the concept of the Hush Expo app envisioned by Dr. Arch. Antonella Radicchi for the EXPO Milan in 2015, whose mock-up was designed by Dr. Arch. Antonella Radicchi in collaboration with Roberto Lombardo.
Hush City has subsequently been developed and implemented by Dr. Arch. Antonella Radicchi at the Technical University of Berlin, in her role as the Principal Investigator of the following projects:

  •  “Beyond the Noise: Open Source Soundscapes” (2016-2018) funded by the IPODI-Marie Curie Fellowship – People Program (TU Berlin/IPODI grant agreement no. 600209)
  •  “Hush City Mobile Lab” (2018-2020) funded by the HEAD-Genuit Foundation [research grant P-17/08-W].

Project Supervisors: Prof. Dr. Dietrich Henckel (Technical University of Berlin), M.A. Jörg Kaptain (Berlin Senate, Senate Department for the Environment, Transport and Climate Protection).
Soundscape Advisor: Prof. Dr. Brigitte Schulte-Fortkamp (Technical University of Berlin).
Acoustic Advisors: Dipl. Ing. Michael Jäcker-Cüppers (ALD, Technical University of Berlin), Dipl. Ing. Manuel Frost (Berlin Senate, Senate Department for the Environment, Transport and Climate Protection), Dipl. Ing. Mattia Cobianchi (Bowers & Wilkins, UK).


Hush City app is a free, native mobile application, which runs on both iOS and Android operating systems: iOS 9.0 and higher (iPhones 5/5C/5S/SE/6/6Plus/7/7Plus) and Android 5 and higher (any Android based smartphone).
A Titanium platform is used as a framework to record and store the data and a LAMP stack is used as a repository.
Audio data are sampled at 44.100Hz, with a resolution of 16bit. The maximum length of the audio file is 30 seconds.
Pictures are collected at a maximum resolution of 6MP and 24bit color.
Sound pressure levels are calculated as numeric scale values and they are A-weighted (i.e. 45 dB(A)). Leq (equivalent continuous sound level), Lmin (minum sound level) and Lmax (maximus sound level) are also calculated and displayed. NoiseTube’s app libraries have been consulted to select the most appropriate formulas for sound pressure level calculation. These formulas have been also double checked by a team of acoustic advisors involved in the project (see credits list below).

Privacy Policy – Terms and Conditions of Use

Your privacy is important to us. Please review this Privacy Policy and Terms and Conditions carefully.
Click here to download the document.


Why is it important to map and evaluate quiet areas with the Hush City app?

Only in Europe, over 125 million people are affected by noise pollution from traffic every year.
Noise from road traffic alone is the second most harmful environmental stressor in Europe, immediately after air pollution, according to the World Health Organization (WHO). The harmful effects of noise arise mainly from the stress reaction it causes in the human body, which can also occur during sleep. These can potentially lead to premature death, cardiovascular disease, cognitive impairment, sleep disturbance, hypertension and, at the very least, annoyance (EEA, 2017). Along with negative impact on our health, well-being and quality of life, noise pollution’s effects cost us approximately 50/100 billion euros per year (DEGA seminar, 2017).

At the European policy level, in 2002 the European Environmental Noise Directive 2002/49/EC (END) was adopted with the aim of establishing a common approach to avoid, prevent, and reduce the harmful effects of noise pollution among the Members States. The END provides a quantitative methodology based upon acoustical indicators (“LAeq” and “Lden”) to measure noise pollution as sound pressure level, “noise maps” to represent it, and action plans based upon noise-mapping results. Furthermore, the END stresses the importance of protecting and planning urban quiet areas, and establishes the definition of a “quiet area”. Finally, the END calls for informing and involving the public in preparing noise maps and action plans but it does not suggest any strategy to achieve this goal.

As reported in (Schulte-Fortkamp, Dubois, 2006; Licitra et al., 2011; Borchi, 2012; HOSANNA, 2013) the quantitative methodology provided by the END is insufficient to understand the complex nature of noise pollution as it does not consider the influence of people’s perception in the evaluation of the sonic environment, particularly in its characteristic of “quietness”.

In order to compensate this deficiency, in the past decades the soundscape approach has been developed in diverse disciplinary fields by researchers in Europe and beyond who referred to the early concepts from the 1960’s by R. M. Schafer and by the World Soundscape Project group (Karlsson, 2000). Recently, this approach has been proved by the COST Group on Soundscape to be essential to improve the quality of life in urban areas, with regard to noise pollution (Kang at al., 2013). This has also been confirmed by the development of the ISO standard 12913 on soundscape, and by the launch of the European Soundscape Award, sponsored by the European Environment Agency (hereafter as EEA). In Germany, the growing interest for the soundscape approach has also been proved by the launch of the StadtKlang 2015 project in the frame of the Science Year 2015 City of the Future Program: StadtKlang is a digital and interactive platform which aims to collect sounds as representative of German places identity through public participation. Furthermore, the soundscape approach seems to be the most adequate for planning quiet areas to the point that the European Environment Agency has encouraged scholars to experiment with mixed methodologies integrating the soundscape approach into the traditional acoustic ones (EEA, 2014).

Against this background, the Hush City app has been developed in the framework of the “Beyond the Noise: Open Source Soundscapes” project, which validated a novel mixed methodology to identify, assess and plan “everyday quiet areas” in cities, by implementing the soundscape approach, the citizen science paradigm and open source technology.

Whereas traditional plans of quiet areas in agglomerations generally include huge parks and big green areas – identified by applying acoustical criteria (e.g. the Berlin Quiet Areas Plan), we argue that different criteria should be applied by municipalities in the identification of quiet areas in cities: firstly, people’s preferences need to be applied as a criterion.
Furthermore, we argue that “everyday quiet areas” –  small, quiet spots embedded in our neighborhoods, at a walking distance from the places we work and live –need to be identified and protected. “Everyday quiet areas” need to be public and easily accessible to everyone (‘quietness as a commons’, Radicchi, 2017).
Moreover, “everyday quiet areas” shall be identified and evaluated by the citizens, according to their preferences and life style (‘soundscape approach’), by means of a proper participative process taking advantage of new technologies (‘citizen science’).

In order to empower people to collect mixed and diverse data, mobile apps seem to be the most appropriate as they could be used by means of smartphones and carried out by citizens in their everyday life, independently by the researcher (citizen science paradigm). Accordingly, the Hush City app has been developed in order to empower local communities to play an active role in participative processes related to the evaluation and planning of everyday quiet areas in our cities.