International audienceThe use of the urban space as a scenery for popular manifestations reaches back to the origins of Rio de Janeiro's Carnival. The so-called "blocks" are groups of people who go out in greeting, to the sound of amplified music and percussion instruments. In the past decades, this type of expression multiplied exponentially, and, nowadays, hundreds of blocks occupy the city streets in the carnival period. The aim of this paper is to investigate the way the "street blocks" act on the urban ambiance and as modifiers of the perception for its inhabitants
