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Harvey Fletcher

Harvey Fletcher is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Harvey Fletcher rather than just read about it. In short: Harvey Fletcher (September 11, 1884 – July 23, 1981) was an American physicist. Known as the "father of stereophonic sound", he is credited with the invention of the 2-A audiometer and an early electronic hearing aid.

Harvey Fletcher — main illustration
Harvey Fletcher — illustration

Key takeaways

  • Harvey Fletcher belongs to astronomy; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Harvey Fletcher to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Harvey Fletcher from memory before moving on to harder problems.

Reference excerpt

Harvey Fletcher (September 11, 1884 – July 23, 1981) was an American physicist. Known as the "father of stereophonic sound", he is credited with the invention of the 2-A audiometer and an early electronic hearing aid. He was an investigator into the nature of speech and hearing, and made contributions in acoustics, electrical engineering, speech, medicine, music, atomic physics, sound pictures, and education. Following his death, he was credited with collaborating with his doctoral advisor, Robert Millikan, on the Nobel-prize winning oil drop experiment which first determined the charge of the electron.

Early years Fletcher was born in Provo, Utah. He graduated from Brigham Young High School in 1904. He enrolled at Brigham Young University (BYU), graduating in 1907 with a bachelor's degree. He married Lorena Chipman. They were the parents of seven children. Harvey Fletcher was the father of James C. Fletcher, former president of the University of Utah and NASA Administrator and of Harvey J. Fletcher, a BYU math professor.

Graduate work In 1911, Fletcher was the first physics student to earn a PhD summa cum laude from the University of Chicago. His dissertation research was on methods to determine the charge of an electron. This included the oil drop experiment commonly attributed to his advisor and collaborator, Robert Andrews Millikan. 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 still contributed to the 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. After completing his doctorate, he returned to BYU, where he became the head of the physics department. He served in this capacity from 1911 until 1916. Fletcher left BYU to work at Western Electric, establishing himself as a researcher. He organized the founding of the Acoustical Society of America (ASA) in 1929. He joined the Bell Telephone Laboratories' Engineering Staff Research Department where he found great interest in the physics of sound (acoustical science). He worked there from 1933 to 1949, when he became a professor of electrical engineering at Columbia University from 1949 to 1952. He returned to BYU in 1952 to be the director of research. He served in that role as well as being the first dean of the new college of physics and engineering sciences until 1958.

Notable contributions Fletcher's contributions to speech perception are among his best-known work. 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 (commonly known as Fletcher–Munson curves), loudness scaling and summation, and the critical band. At Bell Labs, he oversaw research in electrical sound recording, including the first successful stereophonic recordings, the first live stereo sound transmission, and the production of the first vinyl recording. All of this was done with the help of the conductor of the Philadelphia Orchestra, Leopold Stokowski, between 1931 and 1932. Some of his other accomplishments include the production of the first functional hearing aid, the 2-A audiometer, and the artificial larynx. At Bell Labs, he worked with and was reportedly a tremendous influence on Harold Burris-Meyer, who developed advances in psychoacoustics. Much of his research is considered to be authoritative, and his books, Speech and Hearing and Speech and Hearing in Communication, are notable treatises on the subject.

Honors Fletcher was elected an honorary fellow of the Acoustical Society of America in 1949, the second person to receive this honor after Thomas Edison, 20 years earlier. 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 by the Franklin Institute for physical measurements of audition. He was president of the American Physical Society. He was the first president of Acoustical Society of America (1929–31). 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. In 2010, Fletcher was honored by BYU as the founding dean of its College of Engineering (now the Ira A. Fulton College of Engineering). The Harvey Fletcher Engineering Laboratory Building at BYU is named after him. On April 23, 2016, Fletcher was awarded a posthumous technical Grammy Award for his research and inventions related to stereophonic sound.

Personal life Fletcher was a devout member of the Church of Jesus Christ of Latter-day Saints. He died on July 23, 1981, after a stroke.

References

External links "In Memory of Harvey Fletcher" - a brief biography and collection of links Oral history interview transcript with Harvey Fletcher on 15 May 1964, American Institute of Physics, Niels Bohr Library & Archives Department of Communication Disorders at BYU - Audiology department at BYU Harvey Fletcher Scientist, Father of Stereophonic Sound, Author Fletcher Interview, 1963 National Academy of Sciences Biographical Memoir Materials related to Harvey Fletcher at the L. Tom Perry Special Collections, Harold B. Lee Library, Brigham Young University

Illustrations

Harvey Fletcher illustration

Worked examples

Example 1 — a first encounter with Harvey Fletcher

Start with the simplest possible case. Write down what Harvey Fletcher claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Harvey Fletcher before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Harvey Fletcher ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Harvey Fletcher

In research
Harvey Fletcher appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Harvey Fletcher in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Harvey Fletcher is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1884 births, 1981 deaths, 20th-century American educators, so understanding it makes those chapters shorter.
In everyday life
Look for Harvey Fletcher outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Harvey Fletcher in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Harvey Fletcher means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Harvey Fletcher out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Harvey Fletcher in simple terms?

Harvey Fletcher (September 11, 1884 – July 23, 1981) was an American physicist. Known as the "father of stereophonic sound", he is credited with the invention of the 2-A audiometer and an early electronic hearing aid.

Why does Harvey Fletcher matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Harvey Fletcher?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Harvey Fletcher.

Tags

  • 1884 births
  • 1981 deaths
  • 20th-century American educators
  • 20th-century American inventors
  • 20th-century American physicists
  • ASA Gold Medal recipients
  • Auditory scientists
  • Brigham Young High School alumni
  • Brigham Young University alumni
  • Brigham Young University faculty
  • Fellows of the Acoustical Society of America
  • Latter Day Saints from Illinois

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