Chatty Maps, a project to create the sound map of a city

The din of traffic, the rhythm of the music, the sounds of nature: it is undeniable that the urban sound texture has a significant impact on daily life. Chatty Maps is a fascinating project carried out by Daniele Quercia countrymen, Luca Maria Aiello and Rossano Schifanella which aims to show the map of the "sound composition" of some of the world's great cities.

Currently covers the cities of London, Barcelona, Madrid, New York, Boston, Chicago, Washington, Miami, San Francisco, Seattle, Milan and Rome: their maps were created by probing the endless Flickr database, looking for pictures that were both geo-tagged, categorized both by words related to sounds. The list of related words in sounds has been derived from the tags used on Freesound, another public database of audio clips.

Thanks to a specially designed algorithm, it was possible to sift through thousands of photographs, looking for word matches. This operation made it possible to give rise to what the authors of the project called "Urban Dictionary sound" where various types of sounds are mapped over the entire city. The whole was then simplified by grouping the words into five main categories, displayed on the map: transport, nature, animals, humans, music and mechanical machines.

The maps are freely available: by clicking on a road you can see what the composition of its sound texture. In the context of the project we have also studied the correlation between the mapped sounds and emotions and perceptions of the people, in this case taken from photographs of the tag. It was discovered that the sounds related to humans, such as laughter or chatter, seem to be associated with joy or surprise, while traffic and mechanical sounds are mostly related to negative feelings such as fear and anger.

A similar approach was also used to create a whole other set of maps, this time to identify smells, aromas and stenches: Smelly Maps.