The human visual and auditory senses evolved together. Unlike ears, eyes have lids, and, even in vacuum, a person can apprehend his or her heartbeat, movement of internal organs and blood flow. An example of this perception is unborn children who are aware of their surroundings through sound perception (GAUNDERLACH, Jonathan, 2007).
The auditory sense evolved primarily to increase awareness of one’s surroundings, to detect danger, and to communicate. This research recognises that spatial awareness occurs when the auditory organ receives and neural synapses decipher stimuli. Thus, the auditory sense is the primary channel of comprehension and communication. This premise is based on research and testaments of aurally impaired individuals who report that being deaf is potentially a more serious challenge than is being visually impaired. Children who are born deaf or who lose their hearing ability before language acquisition are at a greater disadvantage than are post-lingually aural disabled individuals because infants acquire a database of connections that link optical with aural memories. These associations promote the development of survival responses to signals, language acquisition and eventually logical thought. If hearing is absent at childbirth, the hearing community and surrounding environment is incompatible with the child’s communicative abilities* (SACKS, Oliver, 1989, 1990).
For the average hearing individual, sound defines the surrounding environment. The sonic character of one’s habitat is a compilation of sounds from a variety of sources. Humans adapt to the acoustics of their natural ecosystems (soundscapes) and the significant differences between aural and olfactory horizons. For example, where dense vegetation exists, the olfactory horizons are significantly closer than are the aural horizons. The Mayan civilization shows evidence of aural manipulations in the architecture of their temples, communities and traditions (ANITEI, Stefan, 2007).
Modern humans have readjusted to urban soundscapes, public gathering spaces and enclosed dwellings. They have accumulated a visual-aural associated memory for generations. Among the oldest sounds that have mediated the human species’ acoustic perception are geographic sonic textures such as windshield factor, adjacent bodies of water, vegetation, topography and the sounds of other species. Culture, language and communal interactions outline the overall regional pitch (BLESSER, Barry and Salter, Linda-Ruth, 2006). Post-industrial revolution technology creates noise, a polluting agent (1893). Recent research puts it more accurately: Technology creates a background of ambient sounds (SCHAFER, R. Murray, 1993). Some artists dub this phenomenon as the natural rhythm of the city (FONTANA, Bill, 2011).
There is an argument for experimental design based on individuals’ abilities to comprehend their surroundings through auditory spatial awareness. This process is a neurological conscious and unconscious reaction to spatial acoustics. When the receiver (i.e., listener) is subjected to a sonic event, physical sound waves are transformed into neural signals, sound is detected, and a cognitive process transforms the raw sensation into awareness. A visceral response is also triggered in which an elevated state of mental and physical awareness occurs (BLESSER, Barry and Salter, Linda-Ruth, 2006).
*In Seeing Voices, Oliver Sacks explains that pre-lingually impaired individuals can still learn language and rational thought if they adopt a language compatible to their abilities, namely sign language. He explains that if a community (e.g., Martha’s Vineyard, MA) adopts sign language, aurally impaired individuals will live normally within that community (SACKS, Oliver, 1989, 1990).