Language and culture aside:
Ecologically speaking, vision tends to give us information about the solid features of our environment, and about how they move in relatively continuous relation to us. Concerns like horizon, topography, figure vs. ground, are apprehended all at once and continuously, in the azimuth of the visual field. Vision is, in a way, the sensory mediator of the continuous present. We register movement, but then forget it quickly. We register change, but only keep track of it rarely. The normal concern in vision is with continuous change or with stable distinctions; to be concerned with temporal discontinuity, rupture, or discontinuous change, a viewer must invest something special.
Audition, by contrast, gives us more information about sudden or temporary changes. Background noise quickly vanishes from consciousness, hearing disengages until further notice. But with breakage (snap), rupture (pop), obstacles (thud), flow (whoosh), the ear knows almost instantly what is happening. Sounds of discrete and fleeting events capture our attention entirely, even against our will. An unfamiliar audible disturbance in the next room—even a quiet one—can interrupt anything, a thought, a task, an important question. Whatever you were thinking or saying during such surprises in hearing will have to be repeated after the disturbance has passed, or becomes familiar. Sure, we notice visual disturbances, too — the orange glow of a fire or darkness of a new hole in the ground — but they are rare and dramatic. (They have to be, or we won’t notice them as well.) The same distracting effect is possible in audition with much less effort: a twig breaks, a bird flaps its wings, pepples tumble from a cliff above.
Audition marks specific events, changes in the logic of a situation, and cause-effect relationships. Sounds come less from objects than from the things they do, and when they cease or change what they do, so follows the sound itself. Thus sound is bound to specific events, and marks those events. Counterintuitively, the capacity of sound to mark an event is memorable and stable, even as the sound itself fades: even when the ‘sound itself’ of a footstep in the gravel has quickly disappeared, our sense of its characteristics, location, and timing all stay, object like, in the stores of the sensory system, to mark the event. By contrast, if our visual experience of a (silent) event is fleeting and dynamic, our sense of its relations and movements are fraught with uncertainty; normally we want to see it again in order better to understand it.
Vision and hearing in language and culture:
When it comes to language and culture, our vision — through decoration, clothing, body movement, posture, face, etc. — conveys tone, mood, status, and background experience. The word “status” almost says it all—the conveyance of vision is always in the present, but never only about the present. From what our eyes bring to us, we infer a message, from the past or from the future.
Written language works this way. Unlike speech, visualized words tend to convey something about the future or the past. Something “put it in writing” has stability, and a power to communicate to the future; when we say that plans are “not set in stone” we imagine written words set in something softer, something unstable. But now the writing suggests a dialogue between future and past. Sign-language is an exception to this rule, as it replaces aural communication for subjects with hearing-impairment.
Many have argued that human cultures could nevertheless have evolved with sign-language as their primary language forms, obtaining great advantages as a result, even if hearing was adept in all their participants. Advanced communication during hunting would be more stealthy; communication over moderate distances or in the midst of background noise would be less impaired. The fact that human cultures privilege sound as the mode for speech—as a mode of represention of immediate and dynamic states—tells/shows us something about the information ecology of human senses. Namely: vision is traditionally off-limits to the expression of the complex dynamic present. We reserve it instead for the larger forms and processes, the semi-static, transcendant, or ongoing features of the world. Semifore is a 19th-century exception, texting is a contemporary one. It’ll be inteteresting to see whether increasingly mobile display technologies will dislodge any of these crude generalities.