Technical Meetings

December 2 1999
Ron Sauro, of Northwest Audio and Acoustics, gave a demonstration of the acoustics and sound design program EASE 3.0. EASE was demonstrated with a laptop PC projection, and amplified sound projection. A photograph of Ron Sauro at the keyboard is shown to the right. The overall impression from the presentation is the rapidly advancing capability of such software. 3D rendering assistance in modeling rooms, extensive libraries of absorptive materials and loudspeakers, and flexible visualization of sound fields. Direct sound, early arrivals, ray patterns, reverberations are easily visualized. It is apparent that the user of such a program has a very powerful tool that can be used to understand the acoustic nature of a given space, and to diagnose and solve problems associated with the geometry of particular rooms. Minutes of the Business Portion of the Meeting

April 9 1999
A presentation entitled "Sonic Boom Propagation in a Turbulent Atmosphere" by Andrew Piascek was the feature event at the spring meeting of the Inland NW Regional chapter. Pictured to the right is Andrew Piacsek at the meeting. The discussion began with the anatomy of a sonic boom. The shape of the wavefront was described as it is formed by a supersonic aircraft, and the nonlinear processes that accumulate and form the "N" shape of the waveform. After describing the anatomy of a shock wave, Andrew proceeded to describe the two competing processes that determine the severity of the shock once it is perceived by humans, 1) focusing due to turbulence, and 2) nonlinear processes that accumulate during the focusing process. Whether or not the "swallowtail" waveform is observed depends upon interplay of these two factors. These two factors are in turn determined by the distribution of turbulence in the atmosphere. Large scale turbulent structures cause long focal paths, which give time for nonlinear processes to eliminate the "swallowtail" waveform. Small turbulent structures cause short focal paths, so that nonlinear processes do not have the opportunity to wash out the "swallowtail" waveform. Minutes of the Business Portion of the Meeting

January 28 1999
A presentation by Dr. Margaret Mortz, and her colleagues, Dr. Nancy Vaughn, Nirmala Balasingham, and Min-sung Koh was the featured event of the Fall 1998 meeting of the Inland NW Regional Chapter of the ASA. Pictured to the right are Andy Krause, Phil Marston, Nancy Vaughan, David Egolf, and Jeff Burnett at the pre-meeting dinner that was held in Moscow Idaho. The topic of the presentation was the development of signal processing developments for the enhancement of speech. Dr. Vaughan outlined a strategy for transforming speech signals in ways that lead to enhancement of speech perception. These include emphasizing certain consonant sounds, and modifying the length of speech components. Dr. Mortz and Nirmala Balasingham described their efforts to encode the speech enhancements in signal processing algorithms. These algorithms transform a digitized speech signal automatically to enhance consonant sounds, and other enhancement strategies described by Dr. Vaughan. Finally, Min-sung Koh outlined a new research program that is now being initiated. It involves the use of neuro-fuzzy algorithms to classify speech signals into components. These components can then be transformed and reassembled. Minutes of the Business Portion of the Meeting

February 26 1998
A presentation by William O'Brien from the University of Illinois, Urbana Champagne was the featured event at the Inland NW Regional Chapter Spring Meeting. Dr. O'Brien discussed the historical development of the applications of ultrasonics to medical imaging. In particular, the issue of safety was addressed.

William O'Brien, Center =>

December 16, 1997
A presentation by Terry Baird was the featured event of the Inland NW Regional ASA Chapter Winter meeting. Terry Baird is the Acoustics Test Engineer at the Hewlett Packard Boise site. The Hewlett Packard site is primarily responsible for design and/or manufacture of laser printers and RAID mass storage units. Terry described the efforts that are being made at the Boise site to improve the acoustic performance of their products. Acoustic measurements are taken in a 7mx6mx4m semi-anechoic room, instrumented with thirteen channels of measurement quality microphone instrumentation. In this chamber, measurements of sound power level, sound pressure level, impulsive noise, and prominent discrete tones are made in accordance with ISO 7779 and 9296. Acoustic measurements are used for diagnosing mechanical problems, such as bearing noise, and for reducing noise levels objectionable to consumers. Current efforts are directed toward identifying the components of the overall sound power spectrum that are most annoying to consumers. These components include impulsive noise, and prominent tones. The ISO standards for measurement of impulsive noise and prominent tones is somewhat insufficient for this task, and HP has conducted some research into these topics using focus groups. Future directions for improvement of the acoustic performance of computer equipment include collecting further information from jury or focus groups on annoyance levels, and a Design For Acoustics (DFA) set of guidelines to assist design engineers in preventing objectionable acoustic components early in the design process. Minutes of the Business Portion of the Meeting

April 11, 1997
Nancy Vaughan of Washington State University in Spokane Washington gave a presentation entitled "Perception of Time Compressed Speech by Older Adults". Nancy informed the group that speech compression was orginated by the discovery that humans can comprehend speech even though it has been speeded up, and that some information has been discarded. As the auditory equivalent of "speed reading", this practice has great potential in the areas of education, and the design of user interfaces for machines that rely upon auditory information. In this presentation, Nancy discussed the effect of the degree of compression, the content of the speech being compressed, and the age of the subject on the comprehension of compressed speech. Her studies show that the ability to comprehend compressed speech by humans extends well into middle age, with a significant dropoff as they enter their senior years. Minutes of the Business Portion of the Meeting

April 26, 1996
David N. Lewis of PKN Designs gave a presentation describing his activities as a architectureal acoustical consultant in the Inland NW. An associate, Gary A. Rosenberger, of Moonlight Productions, who often works with David on projects, participated in the presentation. David discussed several projects, ranging from a public announment system in a outdoor rodeo to worship spaces. Discussion of these projects was accompanied by full muli-media presentation, including a high power sound system.

The meeting took place in the Faculty Lounge, Brink Hall, at the University of Idaho. Approximately 14 members were present. A no-host dinner preceeding the presentation was held at the Moscow Hotel for David Lewis and Gary Rosenberger.

October 3, 1995
Dr. Lawrence A. Crum gave a presentation entitled "Acoustical Applications in Medicine". Dr. Crum discussed the activities of his research group at the University of Washington. A lively discussion on the involvement of the Acoustical Society of America in the field of medical ultrasonics followed the presentation.

The meeting was held in McClure Hall, Room 209, at the University of Idaho. A no-host dinner was held for Dr. Crum at the Casa de Oro restaurant before the meeting.

April 27, 1995
Dr. Eugene Trinh of Caltech's Jet Propulsion Laboratory gave a talk on acoustical experiments that have been conducted on the space shuttle. Dr. Trinh was a Payload Specialist on NASA's USML-1 (US Microgravity Laboratory -1) in 1992. He is a fellow of the Acoustical Society of America.