This is a pre-print version of the chapter: Jensenius, A. R. (2017). Sonic Microinteraction in “the Air.” In M. Lesaffre, P.-J. Maes, & M. Leman (Eds.), The Routledge Companion to Embodied Music Interaction (pp. 431–439). New York: Routledge. Sonic Microinteraction in “the Air” Alexander Refsum Jensenius, University of Oslo, Department of Musicology, fourMs lab a.r.jensenius@imv.uio.no Abstract This chapter looks at the ways in which micromotion, the smallest controllable and perceivable human body motion, can be used in interactive sound systems. It presents a general taxonomy, followed by examples of how sonic microinteraction was designed and rehearsed in the scientific-artistic project Sverm. Here, the focus was on micromotion and microaction performed in “the air,” but the concepts developed by the project can also be transferred to other types of microinteraction. 1 Introduction Try to stand still for a couple of minutes. What do you observe? How still can you actually stand? Do you notice the continuous motion of various parts of your body—the rhythmic patterns of your breathing, pulse, and postural adjustments, for example? As a living organism, your body is constantly in motion, even when you try not to move. Researchers have even demonstrated that when people try to stand still on the floor, their heads—the part of the body furthest from the balancing feet—typically move at a velocity of around seven millimeters per second (Jensenius, Bjerkestrand, and Johnson, 2014). Such a quantity of motion might thus be considered the “base level” of a human at a supposed standstill. Following from this, we can propose three rough spatiotemporal levels of human action: 1. Micro: The smallest controllable and perceivable actions, happening at a scale just above the base level—that is, measured in millimeters per second. 2. Meso: Most sound-producing and sound-modifying actions, such as moving the fingers on a keyboard (see Jensenius, Wanderley, Godøy, and Leman, 2010, for an overview of music-related motion). These actions unfold at a scale measured in centimeters per second. 3. Macro: Larger actions, such as moving the hands, arms, or entire body, at a scale measured in decimeters or meters per second. This chapter will look at some of the principles involved in how we might develop conceptual methods and technological systems concerning sonic microinteraction, a type of interaction with sounds that is generated by bodily motion at a very small scale. Here, I use “micromotion” to denote the continuous displacement of an object in time across space at the 1