Separating sound from source: sonic transformation of the violin through electrodynamic pickups and acoustic actuation

When designing an augmented acoustic instrument, it is often of interest to retain an instrument's sound quality and nuanced response while leveraging the richness of digital synthesis. Digital audio has traditionally been generated through speakers, separating sound generation from the instrument itself, or by adding an actuator within the instrument's resonating body, imparting new sounds along with the original. We offer a third option, isolating the playing interface from the actuated resonating body, allowing us to rewrite the relationship between performance action and sound result while retaining the general form and feel of the acoustic instrument. We present a hybrid acoustic-electronic violin based on a stick-body electric violin and an electrodynamic polyphonic pick-up capturing individual string displacements. A conventional violin body acts as the resonator, actuated using digitally altered audio of the string inputs. By attaching the electric violin above the body with acoustic isolation, we retain the physical playing experience of a normal violin along with some of the acoustic filtering and radiation of a traditional build. We propose the use of the hybrid instrument with digitally automated pitch and tone correction to make an easy violin for use as a potential motivational tool for beginning violinists

Nonlinear Dynamical Processes in Musical Interactions: investigating the role of nonlinear dynamics in supporting surprise and exploration in interactions with digital musical instruments

Nonlinear dynamical processes play a central role in many acoustic instruments, yet they rarely feature in digital instruments, and are little understood from an interaction design perspective. Such processes exhibit behaviours that are complex, time-dependent, and chaotic, yet in the context of acoustic instruments can facilitate interactions that are explorable, learnable and repeatable. This suggests that these processes merit deeper investigation for digital music interaction design. Two studies are presented which investigate user interaction with nonlinear dynamical musical tools. A lab-based study used four purpose-built digital musical instruments to test interaction designs featuring nonlinear dynamical processes. Evaluations with 28 musicians demonstrated the potential for these processes to provoke creative surprises, and support exploration without a corresponding loss of control. A subsequent ethnographically-informed study with 24 musicians linked these findings to a mode of engagement which we term ‘edge-like interaction’. Edge-like interactions draw on the complex, unpredictable behaviours found in nonlinear dynamical processes close to critical thresholds, facilitating creative exploration. The two complementary studies provide evidence both for the existing importance of nonlinear dynamical processes in musical interactions with acoustic interactions, and their potential for deployment in the development of new creative digital technologies, musical or otherwise

Extending physical instruments using sampled acoustics

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2007.Includes bibliographical references (p. 133-138).This thesis presents a system architecture for creating hybrid digital-acoustic percussion instruments by combining extensions of existing signal processing techniques with specially-designed semi-acoustic physical controllers. This work aims to provide greater realism to digital percussion, gaining much of the richness and understandability of acoustic instruments while preserving the flexibility of digital systems. For this thesis, I have collaborated with percussionists to develop a range of instruments, to refine and extend the algorithmic and physical designs, and to determine successful models of interaction. Conventional percussion controllers measure and discretize the intensity of strikes into discrete trigger messages, but they also ignore the timbre of the hits and fail to track more ambiguous input. In this work, the continuous acoustic output of a struck physical object is processed to add the resonance of a sampled instrument. This is achieved by employing existing low-latency convolution algorithms which have been extended to give the player control over features such as damping, spectral flattening, nonlinear effects, and pitch.(cont.) One of the advantages of this approach is that light taps, scrapes, rubs, or stirring with brushes all take on a hybrid timbre of the real and sampled sound that is surprisingly realistic and controllable. Since part of its behavior is inherently acoustic, a player's intuition about interacting with physical objects can be applied to controlling it. The ability to transform the apparent acoustic properties of objects also suggests applications to HCI and product design contexts.by Roberto Mario Aimi.Ph.D

Fleeting Strands

stereo acousmatic sound, fixed medi

Personal area networks (PAN) : near-field intra-body communication

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1995.Includes bibliographical references (leaves 80-81).by Thomas Guthrie Zimmerman.M.S

Design and synthesis of non-uniform high impedance surface-based wearable antennas

This thesis is concerned with the design and fabrication of flexible textile wearable antennas integrated with the newly introduced artificial materials known as high impedance surfaces (HIS). With the rapid growth and use of wireless communication systems more and more people are taking advantage of portable computing systems on daily basis. Also with the advancement in electronic industry new and sophisticated wireless devices have been introduced which are being used closed to human body. For user convenience there is an increasing need for integrating antennas on or in the clothing. The conventional antennas being rigid and obtrusive to user movements have limitations. There is a need of antennas made of flexible textile materials that can be part of user clothing defined as wearable antennas. Also with the miniaturisation trend in electronic industry, antenna designers are facing a challenge to come up with a compact, low profile,multi function efficient antenna designs occupying a small physical space. By integrating antennas in user clothing this limited space problem can also be resolved. With the easy availability of electro textile materials it is now possible to manufacture complete fabric antennas. The entire design cycle of wearable fabric antennas starting from material selection to prototype fabrication and antenna testing was carried out in this thesis. A novel technique for antenna fabrication using electro textile material is proposed that will have major implications on wearable computing industry. The use of HIS for antenna performance enhancement is growing at a rapid pace. In this thesis a modified wearable form of HIS defined as non uniform HIS is presented and successfully integrated with antenna for improved performance under low profile limitation. The HIS was also integrated with normal patch antenna to reduce its size and improve its gain and impedance bandwidth. These wearable antennas were then tested under real operating conditions. The measured results validated the design idea and showed that there are many possibilities for these unique artificial materials to be exploited for future wearable on body communication antennas