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All human languages operate with a finite set of distinctively different speech sounds, and the puzzle for Ken was how to explain similarities and differences between these sets. In this area, his best known work concerns development of the “quan- tal theory” of speech sounds. This theory suggest that speech sounds in human languages tend to occur at areas of acoustic stability, that is, areas where lack of precision in movement of the speech articulators—such as tongue, lips, jaw, etc.-- will have minor effects on acoustics. Early on, with his collaborator Sheila Blumstein, Ken also investigated his theory of acoustic invariance—that is, that some portion of the acoustic profile of a speech sound would remain consistent across different words and contexts. This exceedingly “strong” theory influ- enced a generation of research work in speech acoustics and speech perception, but was eventually recast into the Stevens model of distinctive features and landmarks for lexical access. Ken’s interest in the means by which listeners process the acoustics of the speech signal and use this information to rec- ognize words and sentences has also been influential from the earlier days of speech recognition by machine to the current situation, where any user of a smart phone may dictate com- mands using speech. Another testament to the significance of Ken’s research is the 44 year span of his NIH grant “Physiological and Acoustical Studies of Speech”, which focused on analyzing speech across populations of speakers, including children and adults with disordered speech. Ken’s professional legacy was celebrated in the special conference, “From Sound to Sense: 50+ Years of Discovery in Speech Communication”, which drew over 300 former students, post- docs, colleagues and friends to M.I.T. in 2004.
At various times, Ken served in several capacities in ASA. Besides being President from 1976 to 1977, he was the
Chair of the Speech Communication Technical Committee during the organization of technical committees. Additionally, he served as a member of the Long Range Planning Committee and as an Associate Editor of JASA. As ASA President, Ken’s concern for members outside the con- tinental USA led him to suggest holding the first joint meet- ing with the Acoustical Society of Japan in Hawaii, which was a huge success and started a tradition that we keep to this day. At the many conferences that he attended, he was always available to talk with anyone with an interest in acoustics, and especially speech acoustics. His grace and humility was admired and appreciated by all.
Although his capacity for work was a matter of legend, Ken found time for running, biking, and visiting his cabin in Maine, where he indulged a love of the outdoors nurtured during his Canadian upbringing. For many years, he bicy- cled to work on the streets of Cambridge, MA--a daring exercise and not for the faint-hearted. It is thus particularly fitting that his older children by his first marriage to Phyllis Stevens--Andrea, Rebecca, Michael and John--have organ- ized an annual bicycle ride in support of Alzheimer's Disease Research and Treatment. His hobbies included furniture- building and playing the harpsicord. In his 70's, Ken and his second wife, Sharon Manuel, welcomed two daughters from China, Kendra and Mackenzie. When people commented on his long record of productivity, he said they kept him young. He is survived by these members of his family and by five grandchildren as well as numerous other relatives and friends.
Carol Espy-Wilson Suzanne Boyce
Stanley L. Ehrlich, a Fellow of the Acoustical Society of Anerica and a past President of the Society, passed away Wednesday, July 24, 2013 after a brief illness at Charlton Hospital in Fall River, MA. Mr. Ehrlich was born in Newark, NJ, on January 7, 1925 and moved to Providence, RI, the following year. In 1944 he received the Sc.B. degree in Engineering and, in 1945, the Sc. M. degree in Physics, both from Brown University. He also did postgraduate study from 1945 to 1948 at MIT and from 1951 to 1953 at the University of Connecticut, Storrs.
From 1948 to 1953 he was a Physicist at the USN Underwater Sound Laboratory (now the Naval Underwater Systems Center) in New London, CT. From 1953 until his retirement in 1992 he was at Raytheon Company’s Submarine Signal Division in Portsmouth, RI where he was a consulting engineer.
During his career, he was awarded twelve patents on inno- vations in sonar components, many of which are still in use
today. One patent, for which he is especially remembered is US Patent 3,290,646, patented Dec. 6, 1966, titled “Sonar Transducer” and with co- inventor Paul D. Frelich. The invention “provided a unique, lightweight multimode transducer which produced simultaneously two dipole pat- terns with substantially mutually perpendicular acoustic axes and an omnidirectional pattern from plane-wave signals.” What it accomplished, in essence, was a simple piezo-electric device that could sense the incident direction as well as
amplitude of low frequency incident acoustic waves.
Mr. Ehrlich became a member of the Acoustical Society of America in 1949 and over the years worked extensively in the affairs of the Society. He was one of the early recipients, in 1986, of the Society’s Distinguished Service Citation. He served as Chair of the Engineer Acoustics Technical Committee in 1979- 1981, served as Chair of the Committee on Regional Chapters from 1976 to 1985, and served as Chair of the Medals and Awards Committee from 1991 to 1993. He served as Vice-
46 Acoustics Today, October 2013
Stanley L. Ehrlich
1925–2013