audiometry

medicine

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use of electroacoustic equipment in study of hearing

  • human ear
    In human ear: Audiometry

    With the introduction of the electric audiometer in the 1930s, it became possible to measure an individual’s hearing threshold for a series of pure tones ranging from a lower frequency of 125 hertz to an upper frequency of 8,000 or 10,000 hertz. This span…

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oscilloscope, device that plots the relationships between two or more variables, with the horizontal axis normally being a function of time and the vertical axis usually a function of the voltage generated by an input signal. Because almost any physical phenomenon can be converted into a corresponding electric voltage through the use of a transducer, the oscilloscope is a versatile tool in all forms of physical investigation. The German physicist Ferdinand Braun developed the first cathode-ray oscilloscope in 1897.

Speed of response is the oscilloscope’s chief advantage over other plotting devices. General-purpose oscilloscopes have plotting frequencies of up to 100 megahertz (MHz), or 100 million cycles per second. Response times as rapid as 2,000 MHz are achievable with special-purpose high-speed oscilloscopes.

The oscilloscope is one of the most widely used test instruments; its commercial, engineering, and scientific applications include acoustic research, television-production engineering, and electronics design.

barometer. Antique Barometer with readout. Technology measurement, mathematics, measure atmospheric pressure
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The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen.