Known as an industry consultant, lecturer and technical writer, Leonard Feldman contributed to the consumer electronics industry in a variety of ways. As the senior editor of Audio magazine, Feldman wrote reviews that made insightful comparisons of competing consumer electronics equipment in Feldman Labs. He was also a columnist for EQ magazine, and covered various audio and electronic issues in other industry publications such as Popular Electronics and Popular Science, as well as several newspapers. Feldman authored seven books about industry topics in addition.

Feldman was involved in the Audio Engineering Society (AES) as the vice president of the eastern region. Before his death at age 66, Feldman hoped to visit the Toronto section of the AES, but succumbed to cancer before he was able to.