Thursday, September 11, 2014

Harvey Fletcher - the Father of Stereophonic Sound

Setup for the oil drop experiment.
On September 11, 1884, US-american physicist Harvey Fletcher was born. Considered as the "father of stereophonic sound" he is credited with the invention of hearing aids and is well known for his contributions in acoustics, electrical engineering, speech, medicine, music, atomic physics, sound pictures, and education.

Harvey Fletcher was raised in Utah in a religious community. He received his early education at he Brigham Young University where he graduated in 1907. The young engineer then moved to Chicago in order to continue his studies. There, he worked together with Rober A. Millikan measuring the charge of the electron. Their findings in this period highly contributed to the development of radio and television. After successfully performing the oil drop experiment along with Millikan, Fletcher graduated with the first summa cum laude Ph.D. ever awarded by the Physics Department at Chicago. [1,2]

As promised by Fletcher, the scientist returned to Brigham as the chair of the university's physics department. However, he accepted an offer made by the Western Electric Company, and moved to New York in 1916. The engineer had always shown interest in sound and was then responsible to study the fundamentals of human speech-produced sound. He managed to develop the 2-A Audiometer and continued broadly contributing to Bell’s work on sound technologies. It was Fletcher, who guided the development of the Western Electric Hearing Aid, the first device of this kind to use vacuum tubes. [2]

In 1928, Fletcher was appointed director of the director of acoustical research at Bell Labs and was even promoted Director of all Physical Research about seven years later. His first demonstration of stereophonic transmission and stereophonic recording also took place in the 1930s. Reporting on the first presentation of "three dimensional" sound in 1934, the New York Times said that the audience was quite "mystified" and "terrified". Also, it was stated that "Had it not been for the knowledge they were witnessing a practical scientific demonstration, the audience might have believed they were attending a spiritualist seance. Some women in the audience, admitting a feeling of 'spookiness' left the auditorium in fright". Back then, his system used three separate sound channels, in contrast to the two used in modern stereo. [2,3]

Fletcher left Bell Labs at the age of 65 in order to help Columbia University develop a department on acoustics. The engineer also helped found the American Acoustical Society and became its first president. He was elected an honorary member of this Society, an honor which is only shared by Thomas A. Edison. And by the way, Edison was also one of the first to be equipped with Fletcher's innovative hearing aids. However, his experience differed from most of Fletcher's patients. Edison states that "When I used to attend these dinners I sat in silence wondering what the after-dinner speaker was saying and wishing I could hear him, but I was content to turn my thoughts toward some of my inventions. But now with the hearing aid I can hear and understand the speaker but usually find it so dull I turn it off and turn my thought to my inventions." [1]

At yovisto, you may be interested in a short documentary on Harvey Fletcher at Brigham Young University

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