About Cooper Bauck Corporation and Transaural ® Stereo

Cooper Bauck Corporation is the technology developer and patent-holder of the Cooper-Bauck patents and is the entity from which licenses on the patents and associated technology are available.

Cooper Bauck Corporation has licensed the world's largest audio, computer, consumer electronics, and software companies which have used Transaural ® Stereo technology in their products. For example, Harman International uses Transaural ® in their flagship line of Harman Kardon audio/video receivers, where it is known as VMAx ™. The Harman Kardon line has maintained a high level of design excellence and prestige in the audiophile world for decades and Cooper Bauck is proud to have been selected for this application.

Many models of Compaq Computer's Presario line of PC have been made with Transaural ® Stereo technology, and both Compaq and Hewlett-Packard were individually licensed before those companies merged.

Thomson Multimedia, a unit of the large European conglomerate, has used Transaural ® technology in its RCA line of shelf stereo systems. Philips Electronics is also a licensee.

Various semiconductor manufacturers are licensed to make chips with Transaural ® implementations so that a ready supply of parts is available. The latest addition to this list of manufacturers is Texas Instruments. The technology is simple to implement in any digital signal processor (DSP), either commercial, custom, or semi-custom.

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The Technology

Transaural ® Stereo technology is actually a collection of concepts based on the theory of head-related transfer functions and implemented as specially-developed state-of-the art computer algorithms. (Analog designs are also possible.) Head-related transfer functions (HRTF) describe the precise way that sound behaves in the vicinity of a person's head and body. HRTFs can be measured, usually on an acoustical mannequin, and then become the starting point for making a so-called crosstalk cancel er, XTC. A well-designed XTC will allow the sounds at a listener's ears to be prescribed accurately so that the listener hears precisely what was intended by the producer of an audio or musical program. Duane Cooper and Jerry Bauck, while building on the research work of others, were the first to develop the ability to to this accurately, robustly, and economically.

While the development of these algorithms required the application of many very highly theoretical concepts, the actual algorithms can be implemented quite simply by almost anyone with a basic understanding of DSP programming. Implementers have found that once they are supplied with a block diagram and a list of numerical parameters, a typical Transaural ® algorithm can be up and running in a matter of hours.

Once a good XTC is available, it becomes possible to define a listener's ear sounds so that they are the same as the sounds that would result from listening to a five channel ("5.1") home theater, but using only two loudspeakers. Originated by Cooper and Bauck, this is usually known as a "virtual theater" or a "virtual home theater" and is the application that has been the most popular with licensees.

Cooper Bauck Corporation has several designs ready for rapid deployment in a new product. It is also possible to have a custom design made for your product which product may have unusual acoustical properties or for which an uncompromised design is desired (or, for that matter, a very low-cost design). A highly specialized computer-aided design computer program, along with high-level theoretical and practical experience, are the core of Cooper Bauck's design expertise.

We will work as closely as necessary with your engineering staff to see that the algorithm is implemented quickly and correctly so that your product development can proceed apace.

Please read here about the use of Transaural ® Stereo in music recording.

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Licensing

Licensing terms are negotiated with the licensee's special needs considered. Cooper Bauck Corporation is experienced in developing licenses and can work efficiently with your licensing department. We are eager to see this technology employed and offer competitive terms, even against inferior technologies.

E-mail licensing@cooperbauck.com or call 480.839.3708 in the United States.

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Reviews and Commentary in the Press

Transaural ® Stereo has received several notices in the audio and audio/video press, including the "audiophile" press. (These links are to PDF files. If you need the free Acrobat Reader, download it here. Mac OS X users may use the Preview application that is already on on their computer.)

•  IEEE Spectrum (240 KB PDF)
•  Sound & Vision (472 KB PDF)
•  Stereo Review 1 (4 KB PDF)
•  Stereo Review 2 (3 MB PDF)
•  The Perfect Vision (508 KB PDF)

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Applications of the Technology

While the core of Transaural ® technology, the crosstalk canceler, was conceived to make recordings of music and other acoustical events, it also serves as the main tool in creating other devices which can serve in other applications. A few examples are:

• Supremely accurate music recordings.
• Virtual Home Theater (see above)
• Re-rendering multichannel recordings for a different number of channels.
• Air traffic control
• Audio displays for commercial and military pilots. (Reduces cognitive load of pilots by, for example, supplying directionalized synthesized sounds to indicate presence and direction of other aircraft.)
• Directionalization of exterior sounds to occupants of enclosed ground vehicles.

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Contact Us

• contact@cooperbauck.com
• 480 839 3708 (United States)

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