Harvey Fletcher

Harvey Fletcher

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Harvey Fletcher was an American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

. Known as the "father of stereophonic sound" he is credited with the invention of the audiometer
Audiometer
An audiometer is a machine used for evaluating hearing loss. Audiometers are standard equipment at ENT clinics and in audiology centers. They usually consist of an embedded hardware unit connected to a pair of headphones and a test subject feedback button, sometimes controlled by a standard PC...

and hearing aid
Hearing aid
A hearing aid is an electroacoustic device which typically fits in or behind the wearer's ear, and is designed to amplify and modulate sound for the wearer. Earlier devices, known as "ear trumpets" or "ear horns", were passive funnel-like amplification cones designed to gather sound energy and...

. 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.

Early career


Fletcher was born in Provo
Provo, Utah
Provo is the third largest city in the U.S. state of Utah, located about south of Salt Lake City along the Wasatch Front. Provo is the county seat of Utah County and lies between the cities of Orem to the north and Springville to the south...

, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

. He graduated from Brigham Young High School
Brigham Young High School
Brigham Young High School was a private high school in Provo, Utah, first known as Brigham Young Academy, later attached to Brigham Young University and operated under the Church Educational System of The Church of Jesus Christ of Latter-day Saints .- History :When Brigham Young Academy was...

 in 1904. He enrolled at Brigham Young University
Brigham Young University
Brigham Young University is a private university located in Provo, Utah. It is owned and operated by The Church of Jesus Christ of Latter-day Saints , and is the United States' largest religious university and third-largest private university.Approximately 98% of the university's 34,000 students...

 (BYU) and graduated in 1907 with a bachelor's degree. As a graduate student at the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...

, 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
Robert Millikan
Robert A. Millikan was an American experimental physicist, and Nobel laureate in physics for his measurement of the charge on the electron and for his work on the photoelectric effect. He served as president of Caltech from 1921 to 1945...

. Professor Millikan took sole credit, in return for Fletcher claiming full authorship on a related result for his dissertation. Fletcher's contributions were detail-oriented but necessary for a successful experiment, in which he incorporated, among other things, experience with projection lanterns. 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.

Later years


Among the work that he is best known for are Fletcher's contributions to the theory of speech perception
Speech perception
Speech perception is the process by which the sounds of language are heard, interpreted and understood. The study of speech perception is closely linked to the fields of phonetics and phonology in linguistics and cognitive psychology and perception in psychology...

. He showed that speech features are usually spread over a wide frequency range, and developed the articulation index
Articulation index
The Articulation Index is a tool used by audiologists to predict the amount of speech that is audible to a patient with a specific hearing loss. The AI reading for a given patient can range from zero to 1.0, representing the proportion of the average speech signal that is audible...

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. As Director of Research at Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...

, he oversaw research in electrical sound recording, including more than 100 stereo recordings with conductor Leopold Stokowski
Leopold Stokowski
Leopold Anthony Stokowski was a British-born, naturalised American orchestral conductor, well known for his free-hand performing style that spurned the traditional baton and for obtaining a characteristically sumptuous sound from many of the great orchestras he conducted.In America, Stokowski...

 in 1931-2.

Much of his research is considered to be authoritative, and his books, Speech and Hearing and Speech and Hearing in Communication, are landmark treatises on the subject.

Honors


Dr. Fletcher was elected an honorary fellow of Acoustical Society of America
Acoustical Society of America
The Acoustical Society of America is an international scientific society dedicated to increasing and diffusing the knowledge of acoustics and its practical applications.-History:...

 in 1949, the second person to receive this honor after Thomas Edison
Thomas Edison
Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

. 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
Audio Engineering Society
Established in 1948, the Audio Engineering Society draws its membership from amongst engineers, scientists, other individuals with an interest or involvement in the professional audio industry. The membership largely comprises engineers developing devices or products for audio, and persons working...

. In 1924 he was awarded the Louis E. Levy Medal for physical measurements of audition by the Franklin Institute
Franklin Institute
The Franklin Institute is a museum in Philadelphia, Pennsylvania, and one of the oldest centers of science education and development in the United States, dating to 1824. The Institute also houses the Benjamin Franklin National Memorial.-History:On February 5, 1824, Samuel Vaughn Merrick and...

. He was President of the American Physical Society
American Physical Society
The American Physical Society is the world's second largest organization of physicists, behind the Deutsche Physikalische Gesellschaft. The Society publishes more than a dozen scientific journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than 20...

 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
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...

. 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
Ohio State University
The Ohio State University, commonly referred to as Ohio State, is a public research university located in Columbus, Ohio. It was originally founded in 1870 as a land-grant university and is currently the third largest university campus in the United States...

 Research Foundation.

In 2010, Fletcher was honored by BYU as the Founding Dean of the BYU College of Engineering (now the Ira A. Fulton College of Engineering and Technology
Ira A. Fulton College of Engineering and Technology
The Ira A. Fulton College of Engineering and Technology represents Brigham Young University's engineering discipline and includes the following engineering departments: chemical, civil, electrical and computer, mechanical, and the school of technology...

).

He died on July 23, 1981, after a stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

.

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