All of us have channels of perception that have been underutilized. In our visually-dominated world, it is time to give some more room to the senses that have extra bandwidth.
Creating technology that can be used one-handed, without visual feedback, without auditory feedback, without touch or without focused attention enables your product to be used more widely, in more circumstances, and under more conditions across the spectrum of humanity. This principle is known as universal design, the idea that products, buildings and environments ought to be created to make them accessible to all people, regardless of age, ability or other individuating features.
At times, the intelligent use of the senses means adding lights in place of tones, adding haptics instead of lights, or adding tones in place of spoken language — the key is to develop a fine sensibility for how the interface will work most successfully. The ultimate goal is to allow users to easily develop fluency in interactions with your technology, whoever they are.
The three senses that are used most commonly in our technology are sight, hearing and touch. Smell, taste, and proprioception are far less commonly used, although proprioception may be gaining steam with the use of virtual reality. Muscle memory can be exceptionally productive to use in some cases — touch typing, for example — because it is the strongest, most durable form of memory, so tasks learned this way can be carried out without conscious attention.
When translating between senses, the ideal is not to simply map from one sense into another, but to create the equivalent experience.
The performance artist Christine Sun Kim created a Face Opera where prelingually deaf performers, including herself at times, create a range of emotive facial expressions in unison, as a chorus: an interpretation of an opera for those who cannot hear music. This is one of the rare creative translations that achieves an analogous experience in a different sense.
Curiously, music does not evoke all the emotions we experience in daily life, and this is perhaps the most unique and unusual aspect of the experience of music. Although music can evoke anger, it cannot evoke either contempt or jealousy. There have been many attempts to explain the way that music evokes emotions, and relate them to pitch, tempo, timbre, major and minor chords and other aspects of music. Yet there is only one observation that seems to hold universally and it is this limited range of emotions that are born out of music. This is perhaps the strongest argument in favor of the idea that some emotions are not, in fact, natural to human beings, and that one day, we may move past them.
This is an experience, regrettably, that the Face Opera cannot capture. In Musicophilia, Oliver Sacks describes patients with musical afflictions from musical auras with epilepsy, to a continuous flow of spontaneous musical inspiration after a near-death experience. Perhaps someday, we will be able to directly induce the spontaneous experience of music in our brains, and of the deaf will be able to experience it. One patient in Musicophilia notes:
I do have fragments of poetry and sudden phrases darting into my mind, but with nothing like the richness and range of my spontaneous musical imagery. Perhaps it is not just the nervous system, but music itself that has something very peculiar about it — its beat, its melodic contours, so different from those of speech, and its peculiarly direct connection to the emotions. It really is a very odd business that all of us, to varying degrees, have music in our heads. (p. 40)