John M. Strawn, Ph.D.

(PDF version)

Professional Profile

  • Several decades of involvement in , , digital , digital signal processing, and .
  • Successful independent consultant in high-level languages and .
  • Seasoned testifying expert witness with litigation experience (patent, copyright, trade secret, classclass action), skilled at explaining complex ideas to attorneys and juries.
  • Ph.D.
  • Former .
  • Prolific author.
  • Experienced manager with long-range research and development experience.
  • Facile with foreign languages and working with people from outside the USA.

Professional Experience

Position Responsibilibies
S Systems Inc. (Owner, 1992-present; Larkspur CA) Full-time independent consultant:

  • Programming hand-crafted and for signal processing, written in C, , , and especially assembler for digital signal processing chips. A list of consulting projects is available separately.
  • Testifying expert witness in patent litigation relating to and source code, digital devices, , media, , signal processing and client/server interactions. A list of expert witness experience is available separately.
Yamaha Music Technologies USA (1989-1991: President; 1987-1989: Vice President; Larkspur CA) Helped establish and manage a nine-person Ph.D.-level research group, including site search, architectural design, construction, move-in, and hiring. Conducted original research on electronic musical instruments and recent technological developments such as micromachining. Extensive experience designing scientific, engineering, and musical object-oriented applications, especially (UNIX). A list of patents is available below. Research on Yamaha’s Vocaloid started in this group.
S Systems Inc. (Owner, 1986-1988; San Rafael CA) This was my first stint as a consultant. A list of consulting projects is available separately.
Lucasfilm/Droid Works (Programmer, 1985-1986; San Rafael CA) Full-time programming experience as an employee, designing signal-processing modules and writing (96-bit VLIW) microcode for the ASP/SoundDroid developed by James A. Moorer. Experience in and video post-production. Extensive work in C (Unix). Another six months full-time experience writing tightly packed assembly code for the TI TMS32010 DSP chip, especially for a two-channel hard-disk record playback unit that played without bugs on the exhibition floor of the National Association of Broadcasters convention, 1986.
University (Doctoral Student, 1976-1985; CA) Nine years programming experience developing code in high-level languages (Algol, Fortran, SAIL) and PDP-10 assembler for musical and signal processing applications during doctoral thesis work.

My Ph.D. dissertation (Modeling Musical Transitions, 1985) involved original published research in spline fitting, a 30,000-line two- and three-dimensional graphical editor for waveforms and spectra, implementation (with John Gordon) of the short-time Fourier transform, device drivers, and libraries for graphic user interfaces. Also part-time consulting work:

  • SRI International (FORTRAN for mechanical engineering).
  • Mattel Electronics ( in consumer electronic toys).
  • IntelliGenetics (ALGOL-like code for biotechnology).
  • Digital Keyboards (product specification and complete manuals for GDS and Synergy Synthesizers).
Revox (Summer intern, 1972; Long Island, NY) Solder cables, write German- and Dutch-English translations, manufacture PC boards, assemble hardware.

Education and Training


Ph.D., CCRMA, 1985

Advisor: John Chowning. Graduate course work in music, signal processing, computer architecture, assembly-language coding, , acoustics, psychoacoustics, and digital hardware. For the Ph.D. dissertation (Modeling Musical Transitions, 1985) I analyzed articulations and transitions between notes in digitized monophonic musical instrument recordings using the short-time Fourier transform. development experience listed above.

IBM Thomas Watson Foundation

Grant to study electronic , Tokyo, Japan, 1976

Live performances on piano and Roland System 700 analog synthesizer.
Also travel through Turkey, Iran, Afghanistan, Pakistan, India, Thailand, and Hong Kong.

Fulbright Scholar, Technical University Berlin

Berlin, Germany, 1973-74, renewed 1974-75

Graduate-level course work in theory/history, engineering, analog studio electronics, cybernetics, control theory, coding theory, Japanese; all course work in  German. Extensive recording studio and live concert sound reinforcement experience.  PDP-11 and PDP-8 assembler and machine language. Travel throughout Europe.


B. Mus., 1973

Double degree in organ and theory. Experience with electronic music, analog synthesizers, BASIC, FORTRAN, MUSIC V on an IBM 360.


  • Implement/optimize signal processing algorithms: Fourier transform (FFT), discrete cosine transform (DCT), DTMF, speech synthesis.
  • Port/optimize algorithms: AC-3, MP-3, AAC.
  • Implement algorithms: reverberator, pitch shifter, sample rate converter, compressor, filter, flanger, 3-d (Dolby surround), dither.
  • Implement synthesis (additive, physical modeling, wavetable, FM).
  • Create bug-free from academic signal processing research.
  • Work in floating- and fixed-point math.
  • Assembler, object-oriented, C, .
  • Extensive experience optimizing code in assembler
  • PC, Mac, Unix.
  • DSP architectures: Motorola 56000, 56300, and 56800 families; TI TMS320C10 and TMS320C54 family; Code Composer Studio; Analog Devices 21xx family and TigerSharc; VLIW; custom processors; I learn new architectures quickly.
  • Embedded processors: Hitachi SH-DSP, SH3-DSP, SH-4, and SH-5; ARM7/ARM9; configurable processors (Tensilica).
  • .
  • Debugging hardware prototypes.
  • Audio networks, such as AES/EBU (IEC 60958), IEEE-1394/FireWire, AV/C, 61883, mLan, and others.
  • File downloading.
  • Practical experience in live sound and in studios.
  • Testifying expert witness (including expert reports, deposition).
  • Software analysis for litigation including patent, copyright, trade secret, software theft.
  • Functionally bilingual in German; able to read French, Dutch; some Japanese

Expert Witness and Litigation Support Experience

Summary:  15 depositions to date, 3 times testimony at trial.  Patent litigation, ITC investigations, Inter Partes Reviews, USPTO declarations, class action litigation, trade secret litigation, copyright litigation involving software.  Expert reports, declarations, prior art research and analysis, infringement analysis (e.g., analyze devices, documents; source code analysis, source code comparison), claim charts, tutorials, Markman hearings.  Technical areas include and source code; computers, laptops, cell phones, mobile devices, handheld devices (e.g. medical); ; user interfaces; media: , , speech, video; (e.g., MPEG, MP3); digital signal processing, mathematics, algorithms; file downloading, file streaming, client/server; protocols such as internet protocol (IP); video games.  A list of expert witness assignments including deposition and testimony is available separately.

Consulting Experience

Summary: Software in high-level languages (e.g. C, , , Fortran), (digital signal processors, embedded processors, custom processors), and Matlab, for signal processing applications, often related to and . Related projects such as processor design, mergers and acquisitions, feasibility studies, and standards work. A list of consulting projects is available separately.


I was co-inventor on this patent involving micromachining:

5,569,871 1996 Musical tone generating apparatus employing microresonator array

When I was manager of an R&D group for Yamaha, the group was trained by a crack patent attorney on the theory and practice of obtaining  patents. The group was awarded several patents:

5,245,130 1993 Polyphonic breath controlled electronic musical instrument
5,288,938 1994 Method and apparatus for controlling electronic tone generation in accordance with a detected type of performance gesture
5,386,568 1995 Apparatus and method for linking modules
5,422,956 1995 Sound parameter controller for use with a microphone
5,536,902 1996 Method of and apparatus for analyzing and synthesizing a sound by extracting and controlling a sound parameter
5,541,358 1996 Position-based controller for electronic musical instrument

Teaching Appointments

Lecturer, Department of Music & Entertainment Industry Studies, College of Arts & Media, University of Colorado at Denver, 2003-2008. Teach special topics course on data to upper-level undergraduate and graduate students.

Major Publications

Professional Associations and Achievements

  • Fellow (1996), .
  • Convention Co-Chair, 2008 AES Convention, San Francisco.
  • Convention Chair, 2006 AES Convention, San Francisco.
  • Convention Chair, 2004 AES Convention, San Francisco. Recipient of an Anderton Award, Pro Sound News, December 2004, p. 30.
  • Technical Papers co-chair, 2002 AES convention, Los Angeles.
  • Keynote Speaker, November 1996 Convention.
  • Elected member of the AES Board of Governors, 1992-1994; again 2005-2007.
  • Chair, Convention Policy Committee, 2006-2008.
  • Technical Papers chair, 1992 AES Convention, San Francisco (first AES San Francisco Convention).
  • Conference Chair, 1987  International
    Conference on Music and Digital Technology (Los Angeles).
  • Former member of review board, Journal of the .
  • Assistant Editor, Computer Music Journal, 1978-1982.
  • Co-founder (1980), International Computer Music Association.
  • Founder and Series Editor (1984-1996), The Computer Music and Digital Audio Series.
  • Honorary Member (since 1998), The Midi Association, formerly Midi Manufacturers Association (MMA).
  • Technical presentations and session chair at various conferences such as
    , Acoustical Society of America, International Computer Music Conference, DSP World.
  • Conference paper reviewer for many International Computer Music Conferences (ICMC).
  • Member, Acoustical Society of America. Senior Member, IEEE.

Further Qualifications

Functionally bilingual in German. Reading ability in French, Dutch. Some experience with Spanish, Italian, Japanese, Latin. Extensive experience travelling abroad and communicating with foreigners. A list of translations is available separately.

Other activities

I currently enjoy spending time with my family, hiking, and weightlifting. In earlier years I have especially enjoyed travel, aikido, operating a Maerklin Z-gauge model railroad, performing a wide variety of folk and classical , and attending musical events. Member of Toy Train Operating Society of America.


Full vita and references from industry, academia, and lawfirms available on request.

For more information, contact (Dr.) John Strawn.