Ultrasonic Beam Forming: Ongoing Research…

An early prototype of the ultrasonic speaker

The work I have been doing with hyper-directional audio beams  has reached a few notable milestones…

This work consists in part of the ability to direct focussed sound beams dynamically using software or other hardware interfaces.  The sound beams can follow listeners, wander on their own, reflect off walls and bodies, scatter apart and re-form.  “Plains” of sound can spread with emphasis on certain areas within the projected sound field, while creating “nulls” in others.  Multiple beams can be steered with their own dynamic paths.  The technology has great potential and work continues to reach for new possibilities for creating unique sound objects, behaviors and environments.

In the process of consolidating the technology for installation.

 

The custom-designed amplifiers.

The above images shows some of many early prototype ultrasonic arrays.  They have since evolved to be more effective for directing sound and built to be deployable in a variety of installation contexts.  For example, the arrays have been installed on the façade of the Henry Art Gallery as a part of Sanctum, a sound and video installation that is running 24/7 for two and a half years.  They’ve also been mounted on stage for Juan Pampin’s Respiración Artificial, performed by the JACK quartet with Mirta Wymerszberg.

Sanctum_west

Ultrasound Arrays mounted to the façade of the Henry Art Gallery for Sanctum.

 

Experimentation continues… There have been a number of developments in directing the beam in two dimensions–i.e. steering a sound beam on a horizontal and vertical axis–offering more opportunities for new behaviors of sound projection.

A rectangular prototype of a 2D-steering array.

A hexagonal 2-D steering prototype.

Many iterations along with installation and performance opportunities have built out a fairly flexible set of software tool that allow high level control of beam behavior.

Beam control GUIs

An interface for controlling and monitoring beam behaviors, in this case 3 beams.

 

Beam Plane GUI

A simple interface for controlling the strength and direction of multiple concurrent sound beams

I’ve been working on aggregate arrays that offer a larger array “aperture” for more powerful, concise beam formation, more pronounced focusing, spreading and steering.  This also allows more complex projection topology and effective multiple-beam configurations.

A prototype of the aggregate array.

A prototype of the aggregate array.

 

An early prototype of the ultrasonic speaker was installed at the 2011 WOCMAT International Conference on Computer Music and Audio Technology in Taipei, Taiwan.

Ultrasonic Speaker Presented at WOCMAT 2011