The sound installation R$4.00 proposes a resignification of the sound perception of everyday life by means of the registration of an action on public transport in the Greater São Paulo Area. The urban commute is considered a place of passage, a time lapse of waiting between an action that was performed at the source and another action to be materialized upon arrival at a non-place, spaces without associated historical narratives, as defined by Marc Augé (1995: 37):

The installations needed for the accelerated circulation of passengers and goods (high-speed roads and railways, interchanges, airports) are just as much non-places as the means of transport themselves, or the great commercial centres, or the extended transit camps where the planet's refugees are parked.

The public transport environment is thus a time-space that often does not have a specific state of attention, that does not automatically create a narrative. Most of the time passengers stop paying attention to their surroundings and start performing other activities, such as reading a book, listening to music, or above all using their cell phones. According to Michael Bull (2013: 151), “the use of MP3 technologies has become commonplace in the city, with more than 50 percent of the citizens of the industrialized West possessing the ability to create their own privatized and privatizing auditory bubbles as they habitually move through the city.” Isolation from the environment allows the user of these devices to control their experiences, regardless of time and space of displacement. This isolation from the ambient is what Bull calls the endless transit zones of urban culture, characteristic of this increasingly mobile society.

This disconnecting from the outside is subverted in the sound installation R$4.00, which obliges the interactor to be in a hybrid state: both immersive, through the headphones, and “e-mersive,” as he is travelling inside a train carriage.The resignification of the body in public spaces occurs this body is exposed to a sound stimulus that recreates an experience that has been lost or is latent in its memory. Bull (2007: 4) points out that sound reproduction devices, such as iPods or smartphones “stand as both example and metaphor for a culture in which many of us increasingly close our ears to the multi-faceted world through which we daily move.”

For a listener who has never been to São Paulo, experiencing R$4.00 is an opportunity to pay attention to the various sounds of the city’s rail and subway transportation, identifying patterns and making comparisons to similar experiences in other cities.For listeners who have already traveled on São Paulo’s trains and subways, it is a chance to relive this experience and possibly notice a variety of sounds that they may never have perceived before, either due to inattention or headphone use. In this case, the sound file produced during the registration is both a record of a process and the witnessing of a moment that can bring back, in the listener, memories stored in the mind from prior lived experiences. For the historian and Media Studies researcher Maurício Lissovsky (2014: 10), “there is a poetic dimension of its own in the archive. A dimension that is of the order of experience – not only of the experience of time or memories in the strict sense, but of the experience as a place of subjectivation.” So, this past event revives recollections of similar events in one’s memory, reconstituting a possibly personal history that is, at the same time, both a registration as well as a nostalgic sensing. For the Media Studies scholar Luiz Cláudio da Costa (2014), this effect provides an experience between immobilized actuality and multiple virtuality, based on the division of the auditory experience between past time and real time. The sound registration of the journey allows the re-presentation of the space in combination with the listener's memory and imagination.