In this customly built app the surrounding can be explored as a collective Instrument. 

In the following Audio example 20 people installed the app and recorded their selfs whistleing. Then they walked around in a public Space exploring different microsounds and spatializing them as they walk around the space.  Through the dense layering of 20 different instruments the result can be heard as a granular installation where the parameteres are controlled by the sensors of each individual smartphone. 

The sound was coming from the individual smartphone speakers which makes this "instrument" very" accessible, portable and easy to explore