Sigfrid Soli, PhD, an early researcher in cochlear implants, gifted instructor, and co-author of the widely used Hearing in Noise Test (HINT) in hearing aid fitting, died on April 11, 2022.

Sigfrid Soli
Sigfrid Soli, PhD

In 1984, Dr Soli accepted a position as a research scientist at 3M where he worked on the early development of cochlear implants and hearing aid technologies. His research brought him to the world-renown House Ear Institute (HEI) in Los Angeles in 1980 where he and a team of global experts helped bring in this new and, at that time, controversial technology of cochlear implants. Dr Soli spent 23 years at HEI, which included serving as vice president for technology transfer, and traveling extensively in Europe and China to share his expertise with other professionals in his field. As a principal contributor to the development of cochlear implants, he played a significant role in both the creation of tools and methodologies that enhanced the lives of people with severe and profound hearing loss.

Dr Soli was also responsible for helping develop and expand the HINT—one of them most widely used speech discrimination tests to determine how well someone can understand speech in quiet and in background noise—to over 20 different languages.

He worked with researchers throughout the world to develop objective methodologies for the assessment of hearing ability, authoring over 65 scientific publications and being awarded over 30 US and international patents. He was also known for being a dedicated mentor to students, and leaves a legacy of prominent clinicians, researchers, and instructors around the world who benefited from his tutelage.  

Related article: At the Crossroads: An Interview with Sigfrid Soli

According to his obituary, Soli graduated from St Olaf College in 1968, then served as an officer in the US Air Force working on early GPS technology. He received his PhD in Experimental Psychology from the University of Minnesota in 1979 and became a tenured professor in the Psychology Department at the University of Maryland prior to joining 3M.

Dr Soli spent much of his later career in British Columbia, Canada, with frequent stays in Jacksonville Beach, Fla and Kauai, Hawaii. As a distinguished Scientist Emeritus, he maintained dual residency in the United States and Canada and held a faculty position at the University of British Columbia (UBC) in the Department of Audiology and Speech Sciences. Dr Soli never fully retired and remained a mentor and advisor to many. His generous spirit and sense of duty remained.

 “At our School, he generously shared his vast knowledge of the field with anyone who had an interest in the assessment of hearing, and particularly of speech perception abilities,” reads a tribute from UBC. “He will be remembered for his sharp mind, and an uncommon ability to translate research findings into practical applications that have improved the quality of life for people who are deaf and hard of hearing. Both students and colleagues greatly benefitted from his kind and supportive attitude.”

Dr Soli is survived by his wife of 46 years, Susan Egerman Soli; son, Andrew Soli of Los Banos, CA; son, Daniel Soli and wife Jaymee Ho Soli of Squamish, BC; siblings Karen Soli (Joe Holt) of Souix Falls, SD, Peter Soli (Sandy) of Albert Lea, MN, Johanna Boller (Scott Keyes) of St Paul, MN, Tina Lodge (Mark) of Coon Rapids, MN, and many beloved nieces and nephews.

Donations in honor of Sig can be directed to the House Institute Foundation at:

Acknowledgement: Portions of the above were taken or adapted from Dr Soli’s obituary that can be found here.