Floyd E Toole

Imperial College London, Electrical Engineering, Alumnus

National Research Council Of Canada, Applied Physics/Acoustics, senior research officer

The University of New Brunswick, Electrical and Electronics Engineering, Alumnus

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Floyd E. Toole studied electrical engineering at the University of New Brunswick and at the Imperial College of Science and Technology, University of London where he received a Ph.D. In 1965 he joined the National Research Council of Canada in the Division of Applied Physics where he reached the position of Senior Research Officer in the Acoustics and Signal Processing Group. In 1991 he joined Harman International Industries Inc. as Corporate Vice President – Acoustical Engineering. In this position he worked with all Harman International companies and created and directed the Harman Research Group, a central resource for acoustical research and technology development relating to the consumer and professional audio industries. He retired in 2007.
Dr. Toole’s research has focused on the acoustics and psychoacoustics of sound reproduction, directed to improving engineering measurements, objectives for loudspeaker design and evaluation, and techniques for reducing variability at the loudspeaker/room/listener interface. A measurement technique based on his research in the 1980s and further developed in the Harman research group is now a core component in ANSI/CTA-2034-A (2015). “Standard Method of Measurement for In-Home Loudspeakers”, Consumer Technology Association, Technology and Standards Dept., www.CTA.tech.
For his scientific contributions to the audio industry he has been recognized with:
• Two Audio Engineering Society (AES) Publications awards (1988, 1990).
• The AES Silver Medal award (1996).
• The AES Board of Governors Award for service to the society (2003).
• CEDIA Lifetime Achievement award (2008).
• Beryllium Driver Lifetime Achievement award from ALMA (Association of Loudspeaker Manufacturing & Acoustics International) (2011).
• The AES Gold Medal award (2013).
• Inducted into the Consumer Technology Association Hall of Fame (2015).
• The Peter Barnett Award from the Institute of Acoustics (UK) (2017).
He is a Fellow and Past President of the AES, a Fellow of the Acoustical Society of America and a Fellow of CEDIA (Custom Electronic Design and Installation Association).
In addition to numerous publications in magazines, convention preprints and refereed journals, he has authored a book: “Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms.”, Third Edition, Focal Press, 2017. Companion website: www.routledge.com/cw/toole
Phone: 6137965916
Address: 501 - 11 Galt Street
Ottawa, Ontario, K1S 5G4
Canada

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Papers by Floyd E Toole

Subjective Measurements of Loudspeaker Sound Quality and Listener Performance

Journal of The Audio Engineering Society, Feb 1, 1985

ABSTRACT

Hearing is Believing vs. Believing is Hearing: Blind vs. Sighted Listening Tests, and Other Interesting Things

by SEAN OLIVE and Floyd E Toole

The Acoustics and Psychoacoustics of Headphones

... Aided by a close association with Shaw and his work, the author in 1974 (9) began making head... more

Sound Reproduction

Elsevier eBooks, 2007

Listening Tests-Turning Opinion into Fact

Journal of The Audio Engineering Society, May 1, 1981

In‐Head Localization of Acoustic Images

Journal of the Acoustical Society of America, Oct 1, 1970

Listeners placed in an acoustically and visually neutral environment were required to localize so... more Listeners placed in an acoustically and visually neutral environment were required to localize sounds presented by means of loudspeakers. Convincing in-head and external image localizations were observed separately and in combination. The amount of in-head localization was found to change substantially and systematically with changes in signal bandwidth and source position. Signal type and center frequency had less effect. It was concluded that small head movements are not the main factor underlying the "e.•ternalization" of sounds. transducer which moved with the listener's head. He found instead that loudspeakers on either side of the listener produced the most convincing IHL. Hanson and Kock demonstrated IHL with a listener standing equidistant from and facing two loudspeakers. The apparent uncertainty about the circumstances in which IHL may be perceived does not help to resolve the factors underlying the phenomenon. The study The Journal of the Acoustical Society of America 943

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The Perceptual and Physical Dimensions of Sound

Sound in Home Listening Rooms, Home Theaters and Recording Control Rooms

Sound in Cinemas

Sound Production vs. Sound Reproduction

Reflections, Images, and the Precedence Effect

Investigations of these effects go back many decades, and observations of our ability to localize... more

Sound reproduction: Science in the service of art

Journal of the Acoustical Society of America, Apr 1, 2014

A typical example: front left subwoofer only Four subwoofers with Sound Field Management No "aggr... more A typical example: front left subwoofer only Four subwoofers with Sound Field Management No "aggressive" EQ is needed, and all listeners get to hear very similar and very good bass. 113 A Direct Comparison No strong resonances, no audible ringing = "tight" bass. All of this is achieved without low-frequency absorbers! "Sound Reproduction-Science in the Service of Art"

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Investigations of Loudspeaker and Listener Performance

Putting Theory into Practice: Designing a Listening Experience

This chapter attempts to distill the scientific guidance developed in the earlier chapters and ap... more This chapter attempts to distill the scientific guidance developed in the earlier chapters and apply it to the design of home theaters and entertainment spaces. It is taken in stages: the room, video considerations, seating, loudspeaker placement and the multichannel options, and, finally, identifying the basic requirements for loudspeakers to make it all work. The intent is to provide an understanding of how things should be done and why. Ideally, this should enable designers and installers to cope with real-world circumstances—to be adaptable and to be able to find alternatives, knowing what the rigid requirements are and what aspects of design are flexible. Because rooms and loudspeakers are interdependent, we will be discussing which factors matter most, what is less important, and those things that are optional. Fortunately, this is not a matter that demands micrometer precision; some decisions are merely differences, not matters of better or worse, right or wrong. There are opportunities for choice on the part of the designer or to allow interested customers to participate in the design.

The audio industry: The state of our science and art

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Loudspeaker Measurements and Their Relationship to Listener Preferences: Part 1

Journal of The Audio Engineering Society, Apr 1, 1986

Precision measurements on loudspeakers have been possible for some time now and over t�e years. v... more Precision measurements on loudspeakers have been possible for some time now and over t�e years. various views of their importance have developed as a result of accumuiated expenence and scientific investigation. A survey of the literature reveals areas of agreement. and disagreement among workers. There is also evidence of geographic concentratJO�s of loudspeaker designers and reviewers who appear to share attitudes toward speCIfic measureme. loudspeaker measurements In preparatIOn for Part 2. which presents the results of some. current research on the subject.

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Sound in Rooms—Matters of Perspective

The science of room acoustics developed in large performance spaces: concert halls. The sound sou... more The science of room acoustics developed in large performance spaces: concert halls. The sound sources, voices and musical instruments, were considered as a group to be approximately omnidirectional. Sounds from these sources radiate in all directions, being reflected by a few carefully positioned early reflecting surfaces, and then later by many somewhat randomly positioned reflecting, diffracting and scattering surfaces and objects, to create a uniformly mixed reflected sound field that makes its way to all parts of the audience.

Beneficial loudspeaker/room/listener interactions

Journal of the Acoustical Society of America, Oct 1, 2021

Sound reproduction of the highest quality requires an optimized combination of loudspeakers, room... more Sound reproduction of the highest quality requires an optimized combination of loudspeakers, rooms and listeners—electroacoustics, acoustics and psychoacoustics. Domestic and monitor loudspeakers have improved because of research investigating the physical sounds arriving at listeners in small rooms and correlating double-blind subjective ratings of sound quality with relevant anechoic measurements on loudspeakers. Loudspeakers designed using specific anechoic measurements and guidance (e.g., ANSI/CTA-2034-B) reliably yield high sound quality ratings in double-blind listening tests in normally reflective domestic rooms. The relative subjective ratings of loudspeakers remain substantially unchanged when comparison listening tests are conducted in rooms with very different acoustics, although the absolute sound quality has changed. Listeners clearly adapt to some of the essential perceptual characteristics of rooms. But there are limits. About 30% of subjective ratings of sound quality is attributable to bass quality. This is different for every arrangement of loudspeakers and listeners in every different room. Seat-to-seat variations at low frequencies are large. Absorption is traditionally used to damp bass resonances. However, for reproduced sound, multiple subwoofers, with or without signal processing, can manipulate room resonances. These schemes, with equalization, can substantially attenuate audible resonances while yielding much reduced seat-to-seat variation, using no passive acoustical devices.