Although, the architect’s design may directly influence the programmatic aspects of the space, as well as, the relationship among the occupants, the occupants inherently have the control to create a sonic event that temporarily changes the dynamic within the physical space. For example, if one sonic event dominates a single room the aural boundaries could align, extend beyond the physical boundaries, or there could be a matrix of aural boundaries, acting as virtual cubicles, within a physical boundary.
“An acoustic arena is a region where the listeners are a part of a community that shares an ability to hear a sonic event” Blesser, B. and Salter, L.R
When a specific sound source, sound event, is loud enough to be heard, by a group of listeners more clearly than the adjacent events, an acoustic arena is formed. Anyone that cannot hear this sound, even if they can visually see the source, are consider to be beyond the boundary of the arena. As a result, an acoustical arena is volume centered around a sonic event.
Aural spatial awareness is one of the possible channels of information that this thesis is concerned with, along with the information received by the human auditory organ and its many sub channels. A listener can receive information through multiple auditory channels when more than one sonic event exists within their horizon. Hence, a listener can exist in more than one arena simultaneously, receiving information through multiple connections. The sonic event does not necessarily need to be overwhelming. The connection is contingent upon the sonic properties of the auditory channel, and if a sonic event is in close proximity, or loud enough to broadcast information, and establish an auditory connection, then it is consider to be within the listeners acoustic horizon.
“An acoustic horizon is the maximum distance the listener and a source of sound, where the sonic event can still be heard” Blesser, B. and Salter, L.R
Acoustical mirrors, or “listening ears” were used during World War I until they were replaced by radar technology. In fact, in the 1930′s there were attempts to establish a sonic connection between England and France across the channel. However, the reason that these attempts were not completely successful is that the distance the reflection can propagate, is highly dependent on the sensory modality. Lately, science museums exhibit this phenomena as a novelty, where two parabolic surfaces are places 100 meters apart fusing two arenas, at the foci of both surfaces, into one sonic arena. Currently, there are new experimentations conducted in the California Institute of Technology (Caltech), where a grid of small sonic lenses are used to amplify and focus sound energy to a localized point, creating sound bullets (1) .
The auditory demarcation is the equivalent to a visual partition, which delineates an arena or horizon and, therefore, defining an auditory community. This phenomena exists at many scales, from an intimate , personal, conversational, to a public or urban scale. In the abstract, the scale of an arena centered around one sonic event with no interference, is considered to propagate uniformly creating a spherical space. The volume of an intimate arena is approximately 1/2 a meter. The most obvious example is an arena of two people whispering. Less mentioned examples , are the intimate spheres that form within highly noisy environments, like speaking loudly within a nightclub, or on a cliff through a strong gust of wind. A personal arena’s volume is approximately 1 meter in diameter, and the conversational sphere can extend to 4 meters width. These two arenas are exemplified as a normal conversation within a space with a negligent amount of noise. Similarly, these diameters shrink in size within environments with strong interference. Finally, the public and urban scales, which are the concern of this thesis, have significantly larger diameters. The volume is contingent upon the sonic property of the target sound.
Historically, humans adapted to their acoustic environments. Early humans adapted to nature and the great differences between aural and olfactory horizons. For example, where there is thick vegetation, the olfactory horizons are significantly smaller than aural horizons. Hence, the Mayan civilization shows evidence of professing aural manipulation in their temples’ architecture. On the other hand, modern humans have adapted to urban environments, public gathering spaces, and enclosed dwellings.
Broadcasting is not just a human phenomena, on the contrary. Aural communication within a shared acoustic environment is essential to the survival, and part of the complex social habits of various species (Marc D. Hauser 1997 a). Different species use broadcasting in shared environments, where acoustic horizons are much further than that of olfactory horizons like jungles and forests, to attract mates, as warning calls, or establish power. Establishing power by means of broadcasting can be achieved by injecting a sonic event into an acoustic arena. Sonic power is exemplified in historical church bells that became replaced by factory whistles in the beginning of the industrial revolution. In a less obvious way of claiming sonic power, peddlers and shopkeepers in marketplaces use their voices or various musical instruments to attract as many customers as possible. In a modern western society, broadcasting is more to alert rather than to establish political power; which is embodied as amber alerts, airport announcements, or ambulance and police car sirens.
There is an argument comparable to that of public spaces and how they have been renders obsolete lately. Some argue that technology has provided means of creating high quality private acoustic arenas, and provided other means that create social cohesion, making public acoustic arenas less relevant regardless of their noise level. However, this does not explain why festivals and demonstrations are still strong social events. This is evident in Greece where demonstrations are continuously held, or how the ‘Arab spring’ riots have managed to bring about change within their social structure. It would seem that this proves that aural architecture, the principles of auditory arenas, and Alain Corbin’s (1998) studies hold true. Corbin found that an elevated sense of territorial identity is a direct result of soundmarks and regular aural urban architecture .
(1) The ‘Sonic Bullet’ technology is foreseen to be used for noninvasive surgeries. http://www.nature.com/scientificamerican/journal/v302/n6/full/scientificamerican0610-26b.html
(2) Functional Deafness, which is unrelated to biological deafness, is the absence of all acoustic arenas. For example, an individual that is using earphones disconnects him/herself from the all the acoustic channels around, thus they are not within any acoustic arena.
Blesser, B. (2007). Spaces speak, are you listening?: experiencing aural architecture. MIT press.
Castelvecchi, D. (2010). Look, Ma—No Junctions! Scientific American , 26-26.
LaBelle, B. (2010). Acoustic Territories: Sound Culture and Everyday Life. Continuum.