Harvey Fletcher

Harvey Fletcher was an American physicist and engineer known as the father of stereophonic sound. Working at Bell Telephone Laboratories, he directed early research into the physiology of hearing and, with Wilden A. Munson, produced the Fletcher-Munson equal-loudness contours describing how perceived loudness varies with frequency. He led Bell Labs' pioneering 1930s experiments transmitting multi-channel stereophonic sound from the Philadelphia Academy of Music, laying groundwork for modern stereo recording, and later chaired the physics department at Brigham Young University while advancing hearing-aid technology for the deaf. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/