Playful and intuitive stop announcement
Clear and consistent on-board stop announcements are vital to ensure that buses are accessible to and usable by people with disabilities, as well as by visitors or others who may not be familiar with the service area. Without adequate on-board stop announcements some riders may have difficulty knowing when to get off the vehicle.
Traditionally, stop announcements are made manually by vehicle operators using a public address system or provided as part of an automated voice announcement system. For automated voice announcement, vehicle operator can choose between using a text to speech software or pre-recorded voice. In both cases, the message must be clear and not misunderstood.
During the last few years, in addition to the vocal announcement, some vehicle operators have added different types of sounds to the stop announcement in order to increase its attractiveness and to distinguish their company from the others. For example, Paris’ and Strasbourg’ tramway stop announcements were designed by the sound artist Rodolphe Burger. They are made of musical jingles and voices. For each stop, a particular musical jingle and a pair of voices were recorded to design two different stop announcements for each stop. Evocative, playing with our musical memory, the musical jingles are inspired by the names of the stops and allow to introduce the voice announcement. For another example, the composer Michel Redolfi has introduced the concept of “sonal” for the tramways of Nice, Brest, and Besançon. Unlike the jingles (which suggest unchanging and monotonous stop announcement that sounds like a warning), the sonals are designed as musical sounds that can change over time as a function of the environment.
For this project, our intention is to design spatialized intuitive and playful auditory announcements (coupled with the traditional vocal announcement) having a semantic link with the bus stop. Hence, we want to rethink the sounds related to the bus stops by illustrating its with typical auditory icons of the places and of the city. For example, before arriving to the soccer stadium bus stop, a wave will be joined to the traditional announcement voice in order to notify to the passenger the stadium proximity:
While the definition of typical sounds which can be easily identifiable and recognized by all the passengers is simple for few bus stops, the process of finding evocative sounds for all the stop is difficult or impossible. Thus, rather than looking for immediate correspondences between stops’ names and sounds, our approach is to draw inspiration from the identity, the specificity and the history of the places crossed by the bus. In this way, a bike sound at Michelet Ganay stop can inform us that Gustave Ganay was one of the most famous cyclists from the 1920s and that he was native from Marseille:
The sound of stream waters at Valmante stop informs about the presence of an underground river:
An extract of Iannis Xenakis music at Corbusier stop allows the passengers to discover the close links between music and architecture:
With the spatialization of sound, auditory icons travel in the bus following the wave metaphor, giving the sensation of a sound that informs the passengers one by one, starting from the front of the bus and propagating to the back of the bus. In addition to the playful aspect, the use of the sound spatialization allows to attract the passengers attention by opposition to the usual announcement immobility. Different types of waves will be studied as a function of the auditory icon types. Indeed, the simple propagation from the front to back is of interest for some auditory icons while other will be easily perceived with a round trip trajectory or with a circular trajectory (e.g. starting from the right side of the bus and returning by the left side).
By convention, in the bus, a stop is announced twice: the first occur around 100 meters after the previous bus stop, the second takes place around 30 meters before reaching the stop. Depending on the transport company’s or sound designer’s choice, these two types of announcement are differentiated by the voice prosody or by the way they are introduced (using ”next stop is…” or ”stop:…” for example). This differentiation with auditory icons is based on the sound duration. In our system, the first type of announces are associated to a long auditory icons (a sound between 5 and 10 seconds) while second type are associated to short auditory icons (between 1 and 2 seconds):
- 100 meters after the previous stop – long icons:
- 30 meters before the stop – short icons:
Finally, in order not to disturb and bother regular users, only a selection of few stops will be sonified to punctuate the trip. Selected stop and corresponding auditory icons can change according to the time (morning, afternoon, week-end), and to the traffic (peak or off-peak periods).