The acoustics community mourns the loss of two distinguished leaders whose work helped shape modern standards in noise measurement and hearing protection: Richard L. McKinley and William A. Ahroon, Ph.D. Both were dedicated members of the Acoustical Society of America, and Rich was recognized as an ASA Fellow for his significant contributions to the field.
Their passing is a significant loss to the ASA Standards Program and its Accredited Standards Committees for Bioacoustics (S3) and Noise (S12), where their expertise, leadership, and commitment to collaboration made a lasting impact — and to the Acoustical Society of America community as a whole.
Decades of Dedication to Noise Research and Standards
Richard L. McKinley
Rich devoted 40 years of service to the Air Force Research Laboratory at Wright-Patterson Air Force Base. With academic roots in biomedical engineering and signal processing, he built a career focused on
His work helped establish foundational methods that later became part of ANSI standards, including contributions to ASA/ANSI S12.42 and the development of ANSI S12.75 and S12.76 for measuring high-performance aircraft and supersonic jet noise. He collaborated internationally, mentored emerging researchers, and supported innovations in hearing protection for air crews and aircraft carriers.
improving speech intelligibility testing, sound localization methods, and evaluation of hearing protection devices.
Even after retiring from AFRL, Rich continued to serve as a consultant supporting the Air Force. His contributions strengthened communication systems across the Air Force fleet and earned him formal recognition at the national level.
William A. Ahroon, Ph.D.
Bill’s career began in academia after earning his Ph.D. in experimental psychology. His early research advanced understanding of hearing loss mechanisms due to impulsive noise.
He later joined the U.S. Army Aeromedical Research Laboratory (USAARL), where he focused on blast noise exposure, communication systems for service members, and hearing protection related to weapons fire and breaching activities. Bill challenged existing assumptions about impulse noise damage risk criteria and supported rigorous testing of hearing protection devices.
A dedicated mentor, Bill guided soldiers, civilians, and researchers who continue to contribute to hearing science and acoustics today.
Advancing Impulse Noise Standards
Rich and Bill’s work intersected significantly in the study of blast and impulse noise measurement. Their research contributed to multi-agency efforts involving the Air Force, Army Research Laboratory, NIOSH, and universities to better understand damage risk criteria and protective mechanisms for high-level noise exposure.
Both served as subject matter experts during Department of Defense efforts to update military noise standards and evaluate impulse noise damage risk criteria.
In 2013, Dr. Ahroon initiated the revision of ASA/ANSI S12.7, Methods for the Measurement of Impulsive Sound Waveforms. He chaired Working Group 32 for a decade, guiding technical discussions and draft development. Rich later assumed leadership of the revision effort, bringing the work to successful ballot in 2025 and helping guide final comment resolution.
A Lasting Impact
Rich and Bill exemplified the collaborative, consensus-based principles that define the ANSI standards process. Their leadership strengthened national and international standards, advanced hearing protection research, and mentored the next generation of acoustics professionals.
Their contributions will continue to benefit the acoustics community long into the future.
I was fortunate to know both Rich and Bill during my tenure at ASA. I valued their expertise and support throughout
those years. I want to extend my sincere sympathy to their families, friends and colleagues.
Rich was a great colleague of mine. We worked on various standards over the years. Living in the Cincinnati area meant it was an hour or so to get to WPAFB where Rich worked. Rich, David Byrne and I drafted much of the ANSI S12.42 standard over a couple visits to WPAFB in 2008. Hours spent in the library. When Rich and I last spoke it was a few hours of time working on S12.7, the impulse noise measurement standard.
My collaboration with Bill was mainly related to impulse noise. He was always supportive of our research at NIOSH for impulse noise and hearing protection. I visited USAARL several times to use their acoustic shock tube. I helped Bill and the lab install the HPDLAB software that I developed at NIOSH. Bill hated it, too many requirements to make it run. We collaborated on a variety of hearing protection studies, the HPD fit testing interlab study was one of the last we worked on.
They will both be missed.