Seunghun Kim

TAPIR Sound as a New Medium for Music

ABSTRACT The Theoretically Audible, but Practically Inaudible Range (TAPIR) is sound in the highest bandwidth of human hearing; it is barely perceptible by most people but can be transmitted and received by stereotypical transducers. The authors suggest the potential of TAPIR sound as a new medium for music, sonic arts and mobile media.

Toward Certain Sonic Properties of an Audio Feedback System by Evolutionary Control of Second-Order Structures

Aiming for high-level intentional control of audio feedback, though microphones, loudspeakers and digital signal processing, we present a system adapting toward chosen sonic features. Users control the system by selecting and changing feature objectives in real-time. The system has a second-order structure in which the internal signal processing algorithms are developed according to an evolutionary process. Genotypes develop into signal-processing algorithms, and fitness is measured by analysis of the incoming audio feedback. A prototype is evaluated experimentally to measure changes of audio feedback depending on the chosen target conditions. By enhancing interactivity of an audio feedback through the intentional control, we expect that feedback systems could be utilized more effectively in the fields of musical interaction, finding balance between nonlinearity and interactivity.

IAMHear: a tabletop interface with smart mobile devices using acoustic location

IAMHear is a novel tabletop interface for music performance and sound making, in which smart mobile devices are used as on-table objects for interaction. Thanks to the advanced features of smart mobile devices, IAMHear is by nature multi-modal and highly interactive. The system also allows for acoustic location mechanism using virtually inaudible sound without any special sensors, making itself simpler in structure and easier to implement. In addition, use of everyday objects also evokes interaction by intuitive gestures such as placement, movement, and rotation. As a music sequencer, IAMHear enables the user to make music by placing objects on table; inspired by the idea of spectrographic mapping with virtual scan line, pitch and timbre of sounds are determined by the location/orientation of tabletop objects as well as ambient noise. We present IAMHear as a simple and novel alternative to interactive tabletop interface for music and various multimedia applications as well.

Flex-Beam: A Versatile Video Projection Interface for Digital Performance

We present Flex-Beam, a novel projection system designed to enhance and simplify the process of creating projections for digital performances. This system features a motorized reflector to move the projection image as being mounted on a projector and a mobile application to control the system easily without complex interfaces. We evaluated the usefulness and competence of Flex-Beam through three examined interactions for actual live performances: control of the projection position, utilization as a dynamic stage lighting, and creation of a real-time interactive image in motion. The results present that Flex-Beam as an easy-to-use and affordable alternative in digital performances can cover the wide display area with only a projector and create a moving stage lighting/scene regardless of the configuration of a theatre space.

Augmenting Environmental Interaction in Audio Feedback Systems

Audio feedback is defined as a positive feedback of acoustic signals where an audio input and output form a loop, and may be utilized artistically. This article presents new context-based controls over audio feedback, leading to the generation of desired sonic behaviors by enriching the influence of existing acoustic information such as room response and ambient noise. This ecological approach to audio feedback emphasizes mutual sonic interaction between signal processing and the acoustic environment. Mappings from analyses of the received signal to signal-processing parameters are designed to emphasize this specificity as an aesthetic goal. Our feedback system presents four types of mappings: approximate analyses of room reverberation to tempo-scale characteristics, ambient noise to amplitude and two different approximations of resonances to timbre. These mappings are validated computationally and evaluated experimentally in different acoustic conditions.