RESEARCH
> Sound of Things
The goal of this research is to provide natural, seamless sound experiences using smart sound objects.
In recent years, acoustic array technologies incorporating multiple sound objects such as loudspeakers and sensors have changed the way we enjoy the sound. Nevertheless, there are many practical difficulties in realizing acoustic array systems. As the number of sound objects increases, complexity in installation and connection becomes a substantial hurdle. Then, how can we seamlessly integrate and unify multiple sound objects in our ordinary life?
The Sound Of Things paradigm pursues a unified sound system by combining smart sounding objects through unified sound network. The first prerequisite for SoT is to transform any objects or gadgets being used in our ordinary life into smart devices that can produce or measure the sound. The second task is then to identify their own locations through a unified wireless network. With SoT, the floor lamp, coffee table, and light bulbs in a living room can cooperate to act as an active noise control system; a vase, mug, or even window can work together to produce the 3D sound around us. These smart, networked, cooperative objects can realize the sound field we dreamed of producing from acoustic array systems.
The construction of a distributed but unified audio system raises the need to develop both new sound devices and a new control strategy. To accomplish these challenging goals, we set two specific targets in this project: the sound sticker and the smart loudspeaker.
(More detailed introduction on this project can be found from
this article: IEEE Multimedia Magazine http://ieeexplore.ieee.org/document/7535102/)
Sound of Things
Sound Sticker
The sound sticker represents a film-type loudspeaker that can be easily attached to any supporting surface. If one can produce ultra-lightweight thin transducer arrays that can be printed on flexible film and then attached to any chosen surface, the cost and complexity difficulties in constructing huge sound arrays would be solved.
Our current work on sound stickers is mostly based on the thermoacoustic effect that occurs when alternating current is supplied to a conductor. The alternating current induces variations in the Joule effect-induced heating of the conductor, thus producing a density oscillation in a limited portion of the air surrounding the conductor.
(A) Prototype I - (2015) 2D graphene on nanomesh substrate
[Free-Standing Graphene Thermophone on a Polymer-Mesh Substrate, Small, Jan;12(2):185-9 (2015)]
(B) Prototype II - (2016) 3D graphene sponge
[Application of N-Doped Three-Dimensional Reduced Graphene Oxide Aerogel to Thin Film Loudspeaker, ACS Appl. Mater. Interfaces, vol. 8, no. 34, pp. 22295–22300 (2016)]
Smart Sound Network
When many graphene sound stickers or multiple arrays of sound stickers are arbitrarily distributed in space, the optimal driving signal for each sound sticker cannot be determined without knowledge of its position and surrounding environment. Therefore, coordination of the
sound stickers and environment characterization using smart loudspeakers are the key underlying technologies to attain the goal of this project.
In this research, we aim at delivering a smart loudspeaker system based solely on the acoustic waves transmitted and received
between multiple devices. By exchanging inaudible audio signals between sound objects, sound objects can localize their own locations through adaptive audio coordination. These smart sound objects can also trace the location of a user by analyzing scattering information in the measured acoustic signals.
[Self-coordination of multiple sound objects using acoustic signals, 2016]
[Tracking of human location using acoustic scattering waves, 2016]
This research is being supported by Samsung Research Funding Center for Future Technology (SRFC)