Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Review of Primary Methods Applicable to Key Comparisons in Acoustics



Victor Nedzelnitsky


Historically, various techniques have been used in acoustics to attempt to establish and to measure sound pressures in the pressure field (spatially uniform amplitude of sound pressure, as in a suitable coupling cavity that is small compared to a wavelength of sound) and in the free field (plane progressive sound wave at a specified angle of incidence in the absence of reflecting surfaces). At present, over a broad range of frequencies the most accurate, precise, and convenient methods involve the primary calibrations of laboratory standard microphones by reciprocity techniques. Some issues and parameters in these techniques that need to be considered in comparisons, and selected previous interlaboratory comparisons themselves, are discussed. Recommendations relevant to a key comparison already identified, as well as future work areas, are presented.


acoustical measurements, acoustics, calibration of microphones, key comparisons, microphones, primary calibration, reciprocity, sound pressure measurement, standard microphones


Nedzelnitsky, V. (1999), Review of Primary Methods Applicable to Key Comparisons in Acoustics, Metrologia (Accessed February 26, 2024)
Created January 1, 1999, Updated February 19, 2017