Harvey Fletcher

Harvey Fletcher (September 11, 1884 – July 23, 1981) was an American physicist. He is credited with the invention of the hearing aid and the audiometer. He is remembered as a trail-blazing investigator into the nature of speech and hearing, and for his numerous contributions in acoustics, electrical engineering, speech, medicine, music, atomic physics, sound pictures, and education.

Fletcher was born in Provo, Utah, to Charles and Elizabeth Fletcher, he attended local schools. Upon graduation he delivered groceries to pay for his tuition at Brigham Young University (BYU), where he graduating in 1907 and beginning a teaching career there. In 1908 he married Lorena K. Chipman.

Fletcher pursued doctoral studies in physics at the University of Chicago under Robert A. Millikan. As a graduate student, his dissertation research was on methods to determine the charge of an electron. This included the now famous oil drop experiment commonly attributed to his advisor and collaborator, Robert Millikan. Professor Millikan took sole credit, in return for Fletcher claiming full authorship on a related result for his dissertation. Millikan went on to win the 1923 Nobel Prize for Physics, in part for this work, and Fletcher kept the agreement a secret until his death. This fundamental research contributed greatly to the field of electronics and to the development of the radio and television industry.

After receiving a Ph.D. in 1911 (the first physics student at the University of Chicago to graduate summa cum laude) Fletcher returned to teach at Brigham Young University. For five years the Western Electric Company of New York sent him job offers one of which he finally accepted in 1916 and worked for what became the Bell Laboratories until 1949. While working here his genius began to blossom and in course of time he was appointed Director of all Physical Research at Bell Telephone Laboratories.

His work at Bell led directly to high-fidelity recording, sound motion pictures, the first accurate clinical audiometers to measure hearing, the first electronic hearing aid (he was pleased that Thomas Edison wore one of his hearing aids), the development of the artificial larynx, improved telephone transmission, sonar, and stereophonic recording and transmission. He held more than 40 U.S. patents for acoustical devices, published more than 60 major scientific works, and received dozens of awards and honors, including a Presidential Citation from President Harry S. Truman.

The accurate reproduction of sound so intrigued Fletcher that he devoted much of his life to the study of it. In 1933 he created a stir when he demonstrated realistic sound reproduction in an auditorium. The audience members were dumbfounded (and some became frightened and left) when sound simulated airplanes that flew from the front stage and circled overhead. Later the famous conductor Leopold Stokowski cooperated with him in a demonstration of stereophonic sound transmission of a live performance from the Philadelphia Orchestra in Philadelphia to Washington, D.C., where the sound was separated into three channels to achieve realism.

Under Fletcher's administration other researchers at Bell Labs thrived: projects included the developed the transistor (which received the Nobel Prize for this revolutionary device), and the creation the semi-conductor. Other research he supervised now helps ground crews communicate with satellites and guide spacecraft. The development of color TV and advanced medical equipment are other areas in which Bell researchers under his direction made significant contributions.

From 1949 to 1952 Fletcher taught at Columbia University. When he returned to BYU he directed research and helped to set up a new Department of Engineering and the College of Physical and Engineering Sciences. He also researched musical acoustics, working well into his nineties with others to separate each component in the complex web of sound produced by the piano, organ, and string and percussion instruments. Fletcher is known as "the father of stereophonic sound." His technique relied on spaced pairs of microphones. Modern stereo, based primarily on coincident techniques, was independently conceived by Alan Blumlein of EMI at about the same time.

Among the work that he is best known for are Fletcher's contributions to the theory of speech perception. He showed that speech features are usually spread over a wide frequency range, and developed the articulation index to approximately quantify the quality of a speech channel. He also developed the concepts of, equal-loudness contours, loudness scaling and summation, and the critical band.

Dr. Fletcher was elected an honorary member of Acoustical Society of America, an honor which was shared by only one other man—Thomas Edison. He was president of the American Society for Hard of Hearing, an honorary member of the American Otological Society and an honorary member of the Audio Engineering Society. In 1924 he was awarded the Louis E. Levy Medal for physical measurements of audition by the Franklin Institute. He was President of the American Physical Society which is the leading Physics society in America. In 1937 he was elected vice-president of the American Association for the Advancement of Science. He was a member of the National Academy of Sciences. He was also a member of the National Hearing Division Committee of Medical Sciences. He was given the Progress Medal Award by the American Academy of Motion Pictures, in Hollywood. For eight years he acted as National Councilor for the Ohio State University Research Foundation.

Fletcher was the Founding Dean of the BYU College of Engineering (now the Ira A. Fulton College of Engineering and Technology).

He died on July 23, 1981, after a stroke.